[04/18] video/hdmi: Constify infoframe passed to the pack functions

Commit Message

Ville Syrjälä Sept. 20, 2018, 6:51 p.m. UTC

From: Ville Syrjälä <[e-mail]>

Let's make the infoframe pack functions usable with a const infoframe
structure. This allows us to precompute the infoframe earlier, and still
pack it later when we're no longer allowed to modify the structure.
So now we end up with a _check()+_pack_only() or _pack() functions
depending on whether you want to precompute the infoframes or not.
The names aren't greate but I was lazy and didn't want to change all the
drivers.

v2: Deal with exynos churn
    Actually export the new funcs

Cc: Thierry Reding <[e-mail]>
Cc: Hans Verkuil <[e-mail]>
Cc: [e-mail]
Signed-off-by: Ville Syrjälä <[e-mail]>
---
 drivers/video/hdmi.c | 425 +++++++++++++++++++++++++++++++++++++++++++++++----
 include/linux/hdmi.h |  19 ++-
 2 files changed, 416 insertions(+), 28 deletions(-)

Comments

Hans Verkuil (hansverk) Sept. 21, 2018, 8:24 a.m. UTC | #1

On 09/20/18 20:51, Ville Syrjala wrote:
> From: Ville Syrjälä <[e-mail]>
> 
> Let's make the infoframe pack functions usable with a const infoframe
> structure. This allows us to precompute the infoframe earlier, and still
> pack it later when we're no longer allowed to modify the structure.
> So now we end up with a _check()+_pack_only() or _pack() functions
> depending on whether you want to precompute the infoframes or not.
> The names aren't greate but I was lazy and didn't want to change all the

greate -> great

> drivers.
> 
> v2: Deal with exynos churn
>     Actually export the new funcs
> 
> Cc: Thierry Reding <[e-mail]>
> Cc: Hans Verkuil <[e-mail]>
> Cc: [e-mail]
> Signed-off-by: Ville Syrjälä <[e-mail]>
> ---
>  drivers/video/hdmi.c | 425 +++++++++++++++++++++++++++++++++++++++++++++++----
>  include/linux/hdmi.h |  19 ++-
>  2 files changed, 416 insertions(+), 28 deletions(-)
> 
> diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> index 53e7ee2c83fc..9507f668a569 100644
> --- a/drivers/video/hdmi.c
> +++ b/drivers/video/hdmi.c
> @@ -68,8 +68,36 @@ int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
>  }
>  EXPORT_SYMBOL(hdmi_avi_infoframe_init);
>  
> +static int hdmi_avi_infoframe_check_only(const struct hdmi_avi_infoframe *frame)
> +{
> +	if (frame->type != HDMI_INFOFRAME_TYPE_AVI ||
> +	    frame->version != 2 ||
> +	    frame->length != HDMI_AVI_INFOFRAME_SIZE)
> +		return -EINVAL;
> +
> +	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  /**
> - * hdmi_avi_infoframe_pack() - write HDMI AVI infoframe to binary buffer
> + * hdmi_avi_infoframe_check() - Check and check a HDMI AVI infoframe

"Check and check"? This is repeated elsewhere as well (clearly copy-and-paste).

> + * @frame: HDMI AVI infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame)
> +{
> +	return hdmi_avi_infoframe_check_only(frame);
> +}
> +EXPORT_SYMBOL(hdmi_avi_infoframe_check);
> +
> +/**
> + * hdmi_avi_infoframe_pack_only() - write HDMI AVI infoframe to binary buffer
>   * @frame: HDMI AVI infoframe
>   * @buffer: destination buffer
>   * @size: size of buffer
> @@ -82,20 +110,22 @@ EXPORT_SYMBOL(hdmi_avi_infoframe_init);
>   * Returns the number of bytes packed into the binary buffer or a negative
>   * error code on failure.
>   */
> -ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
> -				size_t size)
> +ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
> +				     void *buffer, size_t size)
>  {
>  	u8 *ptr = buffer;
>  	size_t length;
> +	int ret;
> +
> +	ret = hdmi_avi_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
>  
>  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>  
>  	if (size < length)
>  		return -ENOSPC;
>  
> -	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
> -		return -EINVAL;
> -
>  	memset(buffer, 0, size);
>  
>  	ptr[0] = frame->type;
> @@ -152,6 +182,36 @@ ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
>  
>  	return length;
>  }
> +EXPORT_SYMBOL(hdmi_avi_infoframe_pack_only);
> +
> +/**
> + * hdmi_avi_infoframe_pack() - Check and check a HDMI AVI infoframe,
> + *                             and write it to binary buffer
> + * @frame: HDMI AVI infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which packs the information

which packs -> which it packs

Ditto elsewhere.

> + * contained in the @frame structure into a binary representation that
> + * can be written into the corresponding controller registers. Also

Also -> This function also

Ditto elsewhere.

> + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame,
> +				void *buffer, size_t size)
> +{
> +	int ret;
> +
> +	ret = hdmi_avi_infoframe_check(frame);
> +	if (ret)
> +		return ret;
> +
> +	return hdmi_avi_infoframe_pack_only(frame, buffer, size);
> +}
>  EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
>  
>  /**
> @@ -178,8 +238,33 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
>  }
>  EXPORT_SYMBOL(hdmi_spd_infoframe_init);
>  
> +static int hdmi_spd_infoframe_check_only(const struct hdmi_spd_infoframe *frame)
> +{
> +	if (frame->type != HDMI_INFOFRAME_TYPE_SPD ||
> +	    frame->version != 1 ||
> +	    frame->length != HDMI_SPD_INFOFRAME_SIZE)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  /**
> - * hdmi_spd_infoframe_pack() - write HDMI SPD infoframe to binary buffer
> + * hdmi_spd_infoframe_check() - Check and check a HDMI SPD infoframe
> + * @frame: HDMI SPD infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame)
> +{
> +	return hdmi_spd_infoframe_check_only(frame);
> +}
> +EXPORT_SYMBOL(hdmi_spd_infoframe_check);
> +
> +/**
> + * hdmi_spd_infoframe_pack_only() - write HDMI SPD infoframe to binary buffer
>   * @frame: HDMI SPD infoframe
>   * @buffer: destination buffer
>   * @size: size of buffer
> @@ -192,11 +277,16 @@ EXPORT_SYMBOL(hdmi_spd_infoframe_init);
>   * Returns the number of bytes packed into the binary buffer or a negative
>   * error code on failure.
>   */
> -ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
> -				size_t size)
> +ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
> +				     void *buffer, size_t size)
>  {
>  	u8 *ptr = buffer;
>  	size_t length;
> +	int ret;
> +
> +	ret = hdmi_spd_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
>  
>  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>  
> @@ -222,6 +312,36 @@ ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
>  
>  	return length;
>  }
> +EXPORT_SYMBOL(hdmi_spd_infoframe_pack_only);
> +
> +/**
> + * hdmi_spd_infoframe_pack() - Check and check a HDMI SPD infoframe,
> + *                             and write it to binary buffer
> + * @frame: HDMI SPD infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which packs the information
> + * contained in the @frame structure into a binary representation that
> + * can be written into the corresponding controller registers. Also
> + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame,
> +				void *buffer, size_t size)
> +{
> +	int ret;
> +
> +	ret = hdmi_spd_infoframe_check(frame);
> +	if (ret)
> +		return ret;
> +
> +	return hdmi_spd_infoframe_pack_only(frame, buffer, size);
> +}
>  EXPORT_SYMBOL(hdmi_spd_infoframe_pack);
>  
>  /**
> @@ -242,8 +362,33 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
>  }
>  EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>  
> +static int hdmi_audio_infoframe_check_only(const struct hdmi_audio_infoframe *frame)
> +{
> +	if (frame->type != HDMI_INFOFRAME_TYPE_AUDIO ||
> +	    frame->version != 1 ||
> +	    frame->length != HDMI_AUDIO_INFOFRAME_SIZE)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
> +/**
> + * hdmi_audio_infoframe_check() - Check and check a HDMI audio infoframe
> + * @frame: HDMI audio infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame)
> +{
> +	return hdmi_audio_infoframe_check_only(frame);
> +}
> +EXPORT_SYMBOL(hdmi_audio_infoframe_check);
> +
>  /**
> - * hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
> + * hdmi_audio_infoframe_pack_only() - write HDMI audio infoframe to binary buffer
>   * @frame: HDMI audio infoframe
>   * @buffer: destination buffer
>   * @size: size of buffer
> @@ -256,12 +401,17 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
>   * Returns the number of bytes packed into the binary buffer or a negative
>   * error code on failure.
>   */
> -ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> -				  void *buffer, size_t size)
> +ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
> +				       void *buffer, size_t size)
>  {
>  	unsigned char channels;
>  	u8 *ptr = buffer;
>  	size_t length;
> +	int ret;
> +
> +	ret = hdmi_audio_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
>  
>  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>  
> @@ -297,6 +447,36 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>  
>  	return length;
>  }
> +EXPORT_SYMBOL(hdmi_audio_infoframe_pack_only);
> +
> +/**
> + * hdmi_audio_infoframe_pack() - Check and check a HDMI Audio infoframe,
> + *                               and write it to binary buffer
> + * @frame: HDMI Audio infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which packs the information
> + * contained in the @frame structure into a binary representation that
> + * can be written into the corresponding controller registers. Also
> + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> +				  void *buffer, size_t size)
> +{
> +	int ret;
> +
> +	ret = hdmi_audio_infoframe_check(frame);
> +	if (ret)
> +		return ret;
> +
> +	return hdmi_audio_infoframe_pack_only(frame, buffer, size);
> +}
>  EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
>  
>  /**
> @@ -319,6 +499,7 @@ int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame)
>  	 * value
>  	 */
>  	frame->s3d_struct = HDMI_3D_STRUCTURE_INVALID;
> +	frame->length = 4;
>  
>  	return 0;
>  }
> @@ -335,8 +516,42 @@ static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
>  		return 4;
>  }
>  
> +static int hdmi_vendor_infoframe_check_only(const struct hdmi_vendor_infoframe *frame)
> +{
> +	if (frame->type != HDMI_INFOFRAME_TYPE_VENDOR ||
> +	    frame->version != 1 ||
> +	    frame->oui != HDMI_IEEE_OUI)
> +		return -EINVAL;
> +
> +	/* only one of those can be supplied */
> +	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
> +		return -EINVAL;
> +
> +	if (frame->length != hdmi_vendor_infoframe_length(frame))
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  /**
> - * hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary buffer
> + * hdmi_vendor_infoframe_check() - Check and check a HDMI vendor infoframe
> + * @frame: HDMI infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame)
> +{
> +	frame->length = hdmi_vendor_infoframe_length(frame);
> +
> +	return hdmi_vendor_infoframe_check_only(frame);
> +}
> +EXPORT_SYMBOL(hdmi_vendor_infoframe_check);
> +
> +/**
> + * hdmi_vendor_infoframe_pack_only() - write a HDMI vendor infoframe to binary buffer
>   * @frame: HDMI infoframe
>   * @buffer: destination buffer
>   * @size: size of buffer
> @@ -349,17 +564,16 @@ static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
>   * Returns the number of bytes packed into the binary buffer or a negative
>   * error code on failure.
>   */
> -ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> -				 void *buffer, size_t size)
> +ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
> +					void *buffer, size_t size)
>  {
>  	u8 *ptr = buffer;
>  	size_t length;
> +	int ret;
>  
> -	/* only one of those can be supplied */
> -	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
> -		return -EINVAL;
> -
> -	frame->length = hdmi_vendor_infoframe_length(frame);
> +	ret = hdmi_vendor_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
>  
>  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
>  
> @@ -394,24 +608,134 @@ ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
>  
>  	return length;
>  }
> +EXPORT_SYMBOL(hdmi_vendor_infoframe_pack_only);
> +
> +/**
> + * hdmi_vendor_infoframe_pack() - Check and check a HDMI Vendor infoframe,
> + *                                and write it to binary buffer
> + * @frame: HDMI Vendor infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which packs the information
> + * contained in the @frame structure into a binary representation that
> + * can be written into the corresponding controller registers. Also
> + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> +				   void *buffer, size_t size)
> +{
> +	int ret;
> +
> +	ret = hdmi_vendor_infoframe_check(frame);
> +	if (ret)
> +		return ret;
> +
> +	return hdmi_vendor_infoframe_pack_only(frame, buffer, size);
> +}
>  EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);
>  
> +static int
> +hdmi_vendor_any_infoframe_check_only(const union hdmi_vendor_any_infoframe *frame)
> +{
> +	if (frame->any.type != HDMI_INFOFRAME_TYPE_VENDOR ||
> +	    frame->any.version != 1)
> +		return -EINVAL;
> +
> +	return 0;
> +}
> +
>  /*
> - * hdmi_vendor_any_infoframe_pack() - write a vendor infoframe to binary buffer
> + * hdmi_vendor_any_infoframe_check() - check and check a vendor infoframe
> + */
> +static int
> +hdmi_vendor_any_infoframe_check(union hdmi_vendor_any_infoframe *frame)
> +{
> +	int ret;
> +
> +	ret = hdmi_vendor_any_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
> +
> +	/* we only know about HDMI vendor infoframes */
> +	if (frame->any.oui != HDMI_IEEE_OUI)
> +		return -EINVAL;
> +
> +	return hdmi_vendor_infoframe_check(&frame->hdmi);
> +}
> +
> +/*
> + * hdmi_vendor_any_infoframe_pack_only() - write a vendor infoframe to binary buffer
>   */
>  static ssize_t
> -hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> -			   void *buffer, size_t size)
> +hdmi_vendor_any_infoframe_pack_only(const union hdmi_vendor_any_infoframe *frame,
> +				    void *buffer, size_t size)
>  {
> +	int ret;
> +
> +	ret = hdmi_vendor_any_infoframe_check_only(frame);
> +	if (ret)
> +		return ret;
> +
>  	/* we only know about HDMI vendor infoframes */
>  	if (frame->any.oui != HDMI_IEEE_OUI)
>  		return -EINVAL;
>  
> -	return hdmi_vendor_infoframe_pack(&frame->hdmi, buffer, size);
> +	return hdmi_vendor_infoframe_pack_only(&frame->hdmi, buffer, size);
> +}
> +
> +/*
> + * hdmi_vendor_any_infoframe_pack() - check and check a vendor infoframe,
> + *                                              and write it to binary buffer
> + */
> +static ssize_t
> +hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> +			       void *buffer, size_t size)
> +{
> +	int ret;
> +
> +	ret = hdmi_vendor_any_infoframe_check(frame);
> +	if (ret)
> +		return ret;
> +
> +	return hdmi_vendor_any_infoframe_pack_only(frame, buffer, size);
> +}
> +
> +/**
> + * hdmi_infoframe_check() - Check check a HDMI infoframe
> + * @frame: HDMI infoframe
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields.
> + *
> + * Returns 0 on success or a negative error code on failure.
> + */
> +int
> +hdmi_infoframe_check(union hdmi_infoframe *frame)
> +{
> +	switch (frame->any.type) {
> +	case HDMI_INFOFRAME_TYPE_AVI:
> +		return hdmi_avi_infoframe_check(&frame->avi);
> +	case HDMI_INFOFRAME_TYPE_SPD:
> +		return hdmi_spd_infoframe_check(&frame->spd);
> +	case HDMI_INFOFRAME_TYPE_AUDIO:
> +		return hdmi_audio_infoframe_check(&frame->audio);
> +	case HDMI_INFOFRAME_TYPE_VENDOR:
> +		return hdmi_vendor_any_infoframe_check(&frame->vendor);
> +	default:
> +		WARN(1, "Bad infoframe type %d\n", frame->any.type);
> +		return -EINVAL;
> +	}
>  }
> +EXPORT_SYMBOL(hdmi_infoframe_check);
>  
>  /**
> - * hdmi_infoframe_pack() - write a HDMI infoframe to binary buffer
> + * hdmi_infoframe_pack_only() - write a HDMI infoframe to binary buffer
>   * @frame: HDMI infoframe
>   * @buffer: destination buffer
>   * @size: size of buffer
> @@ -425,7 +749,56 @@ hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
>   * error code on failure.
>   */
>  ssize_t
> -hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size)
> +hdmi_infoframe_pack_only(const union hdmi_infoframe *frame, void *buffer, size_t size)
> +{
> +	ssize_t length;
> +
> +	switch (frame->any.type) {
> +	case HDMI_INFOFRAME_TYPE_AVI:
> +		length = hdmi_avi_infoframe_pack_only(&frame->avi,
> +						      buffer, size);
> +		break;
> +	case HDMI_INFOFRAME_TYPE_SPD:
> +		length = hdmi_spd_infoframe_pack_only(&frame->spd,
> +						      buffer, size);
> +		break;
> +	case HDMI_INFOFRAME_TYPE_AUDIO:
> +		length = hdmi_audio_infoframe_pack_only(&frame->audio,
> +							buffer, size);
> +		break;
> +	case HDMI_INFOFRAME_TYPE_VENDOR:
> +		length = hdmi_vendor_any_infoframe_pack_only(&frame->vendor,
> +							     buffer, size);
> +		break;
> +	default:
> +		WARN(1, "Bad infoframe type %d\n", frame->any.type);
> +		length = -EINVAL;
> +	}
> +
> +	return length;
> +}
> +EXPORT_SYMBOL(hdmi_infoframe_pack_only);
> +
> +/**
> + * hdmi_infoframe_pack() - Check check a HDMI infoframe,

Check check?

> + *                         and write it to binary buffer
> + * @frame: HDMI infoframe
> + * @buffer: destination buffer
> + * @size: size of buffer
> + *
> + * Validates that the infoframe is consistent and updates derived fields
> + * (eg. length) based on other fields, after which packs the information
> + * contained in the @frame structure into a binary representation that
> + * can be written into the corresponding controller registers. Also
> + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> + * specification.
> + *
> + * Returns the number of bytes packed into the binary buffer or a negative
> + * error code on failure.
> + */
> +ssize_t
> +hdmi_infoframe_pack(union hdmi_infoframe *frame,
> +		    void *buffer, size_t size)
>  {
>  	ssize_t length;
>  
> diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> index bce1abb1fe57..c76b50a48e48 100644
> --- a/include/linux/hdmi.h
> +++ b/include/linux/hdmi.h
> @@ -163,6 +163,9 @@ struct hdmi_avi_infoframe {
>  int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame);
>  ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
>  				size_t size);
> +ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
> +				     void *buffer, size_t size);
> +int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame);
>  
>  enum hdmi_spd_sdi {
>  	HDMI_SPD_SDI_UNKNOWN,
> @@ -194,6 +197,9 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
>  			    const char *vendor, const char *product);
>  ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
>  				size_t size);
> +ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
> +				     void *buffer, size_t size);
> +int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame);
>  
>  enum hdmi_audio_coding_type {
>  	HDMI_AUDIO_CODING_TYPE_STREAM,
> @@ -272,6 +278,9 @@ struct hdmi_audio_infoframe {
>  int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
>  ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
>  				  void *buffer, size_t size);
> +ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
> +				       void *buffer, size_t size);
> +int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame);
>  
>  enum hdmi_3d_structure {
>  	HDMI_3D_STRUCTURE_INVALID = -1,
> @@ -299,6 +308,9 @@ struct hdmi_vendor_infoframe {
>  int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame);
>  ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
>  				   void *buffer, size_t size);
> +ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
> +					void *buffer, size_t size);
> +int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame);
>  
>  union hdmi_vendor_any_infoframe {
>  	struct {
> @@ -330,8 +342,11 @@ union hdmi_infoframe {
>  	struct hdmi_audio_infoframe audio;
>  };
>  
> -ssize_t
> -hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size);
> +ssize_t hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer,
> +			    size_t size);
> +ssize_t hdmi_infoframe_pack_only(const union hdmi_infoframe *frame,
> +				 void *buffer, size_t size);
> +int hdmi_infoframe_check(union hdmi_infoframe *frame);
>  int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
>  			  const void *buffer, size_t size);
>  void hdmi_infoframe_log(const char *level, struct device *dev,
> 

Regards,

	Hans

Ville Syrjälä Sept. 21, 2018, 2:30 p.m. UTC | #2

On Fri, Sep 21, 2018 at 10:24:25AM +0200, Hans Verkuil wrote:
> On 09/20/18 20:51, Ville Syrjala wrote:
> > From: Ville Syrjälä <[e-mail]>
> > 
> > Let's make the infoframe pack functions usable with a const infoframe
> > structure. This allows us to precompute the infoframe earlier, and still
> > pack it later when we're no longer allowed to modify the structure.
> > So now we end up with a _check()+_pack_only() or _pack() functions
> > depending on whether you want to precompute the infoframes or not.
> > The names aren't greate but I was lazy and didn't want to change all the
> 
> greate -> great

Thanks for reading through it. Fixed up all the crap you spotted.

> 
> > drivers.
> > 
> > v2: Deal with exynos churn
> >     Actually export the new funcs
> > 
> > Cc: Thierry Reding <[e-mail]>
> > Cc: Hans Verkuil <[e-mail]>
> > Cc: [e-mail]
> > Signed-off-by: Ville Syrjälä <[e-mail]>
> > ---
> >  drivers/video/hdmi.c | 425 +++++++++++++++++++++++++++++++++++++++++++++++----
> >  include/linux/hdmi.h |  19 ++-
> >  2 files changed, 416 insertions(+), 28 deletions(-)
> > 
> > diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
> > index 53e7ee2c83fc..9507f668a569 100644
> > --- a/drivers/video/hdmi.c
> > +++ b/drivers/video/hdmi.c
> > @@ -68,8 +68,36 @@ int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
> >  }
> >  EXPORT_SYMBOL(hdmi_avi_infoframe_init);
> >  
> > +static int hdmi_avi_infoframe_check_only(const struct hdmi_avi_infoframe *frame)
> > +{
> > +	if (frame->type != HDMI_INFOFRAME_TYPE_AVI ||
> > +	    frame->version != 2 ||
> > +	    frame->length != HDMI_AVI_INFOFRAME_SIZE)
> > +		return -EINVAL;
> > +
> > +	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> >  /**
> > - * hdmi_avi_infoframe_pack() - write HDMI AVI infoframe to binary buffer
> > + * hdmi_avi_infoframe_check() - Check and check a HDMI AVI infoframe
> 
> "Check and check"? This is repeated elsewhere as well (clearly copy-and-paste).
> 
> > + * @frame: HDMI AVI infoframe
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame)
> > +{
> > +	return hdmi_avi_infoframe_check_only(frame);
> > +}
> > +EXPORT_SYMBOL(hdmi_avi_infoframe_check);
> > +
> > +/**
> > + * hdmi_avi_infoframe_pack_only() - write HDMI AVI infoframe to binary buffer
> >   * @frame: HDMI AVI infoframe
> >   * @buffer: destination buffer
> >   * @size: size of buffer
> > @@ -82,20 +110,22 @@ EXPORT_SYMBOL(hdmi_avi_infoframe_init);
> >   * Returns the number of bytes packed into the binary buffer or a negative
> >   * error code on failure.
> >   */
> > -ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
> > -				size_t size)
> > +ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
> > +				     void *buffer, size_t size)
> >  {
> >  	u8 *ptr = buffer;
> >  	size_t length;
> > +	int ret;
> > +
> > +	ret = hdmi_avi_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> >  
> >  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
> >  
> >  	if (size < length)
> >  		return -ENOSPC;
> >  
> > -	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
> > -		return -EINVAL;
> > -
> >  	memset(buffer, 0, size);
> >  
> >  	ptr[0] = frame->type;
> > @@ -152,6 +182,36 @@ ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
> >  
> >  	return length;
> >  }
> > +EXPORT_SYMBOL(hdmi_avi_infoframe_pack_only);
> > +
> > +/**
> > + * hdmi_avi_infoframe_pack() - Check and check a HDMI AVI infoframe,
> > + *                             and write it to binary buffer
> > + * @frame: HDMI AVI infoframe
> > + * @buffer: destination buffer
> > + * @size: size of buffer
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields, after which packs the information
> 
> which packs -> which it packs
> 
> Ditto elsewhere.
> 
> > + * contained in the @frame structure into a binary representation that
> > + * can be written into the corresponding controller registers. Also
> 
> Also -> This function also
> 
> Ditto elsewhere.
> 
> > + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> > + * specification.
> > + *
> > + * Returns the number of bytes packed into the binary buffer or a negative
> > + * error code on failure.
> > + */
> > +ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame,
> > +				void *buffer, size_t size)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_avi_infoframe_check(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return hdmi_avi_infoframe_pack_only(frame, buffer, size);
> > +}
> >  EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
> >  
> >  /**
> > @@ -178,8 +238,33 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
> >  }
> >  EXPORT_SYMBOL(hdmi_spd_infoframe_init);
> >  
> > +static int hdmi_spd_infoframe_check_only(const struct hdmi_spd_infoframe *frame)
> > +{
> > +	if (frame->type != HDMI_INFOFRAME_TYPE_SPD ||
> > +	    frame->version != 1 ||
> > +	    frame->length != HDMI_SPD_INFOFRAME_SIZE)
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> >  /**
> > - * hdmi_spd_infoframe_pack() - write HDMI SPD infoframe to binary buffer
> > + * hdmi_spd_infoframe_check() - Check and check a HDMI SPD infoframe
> > + * @frame: HDMI SPD infoframe
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame)
> > +{
> > +	return hdmi_spd_infoframe_check_only(frame);
> > +}
> > +EXPORT_SYMBOL(hdmi_spd_infoframe_check);
> > +
> > +/**
> > + * hdmi_spd_infoframe_pack_only() - write HDMI SPD infoframe to binary buffer
> >   * @frame: HDMI SPD infoframe
> >   * @buffer: destination buffer
> >   * @size: size of buffer
> > @@ -192,11 +277,16 @@ EXPORT_SYMBOL(hdmi_spd_infoframe_init);
> >   * Returns the number of bytes packed into the binary buffer or a negative
> >   * error code on failure.
> >   */
> > -ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
> > -				size_t size)
> > +ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
> > +				     void *buffer, size_t size)
> >  {
> >  	u8 *ptr = buffer;
> >  	size_t length;
> > +	int ret;
> > +
> > +	ret = hdmi_spd_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> >  
> >  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
> >  
> > @@ -222,6 +312,36 @@ ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
> >  
> >  	return length;
> >  }
> > +EXPORT_SYMBOL(hdmi_spd_infoframe_pack_only);
> > +
> > +/**
> > + * hdmi_spd_infoframe_pack() - Check and check a HDMI SPD infoframe,
> > + *                             and write it to binary buffer
> > + * @frame: HDMI SPD infoframe
> > + * @buffer: destination buffer
> > + * @size: size of buffer
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields, after which packs the information
> > + * contained in the @frame structure into a binary representation that
> > + * can be written into the corresponding controller registers. Also
> > + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> > + * specification.
> > + *
> > + * Returns the number of bytes packed into the binary buffer or a negative
> > + * error code on failure.
> > + */
> > +ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame,
> > +				void *buffer, size_t size)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_spd_infoframe_check(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return hdmi_spd_infoframe_pack_only(frame, buffer, size);
> > +}
> >  EXPORT_SYMBOL(hdmi_spd_infoframe_pack);
> >  
> >  /**
> > @@ -242,8 +362,33 @@ int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
> >  }
> >  EXPORT_SYMBOL(hdmi_audio_infoframe_init);
> >  
> > +static int hdmi_audio_infoframe_check_only(const struct hdmi_audio_infoframe *frame)
> > +{
> > +	if (frame->type != HDMI_INFOFRAME_TYPE_AUDIO ||
> > +	    frame->version != 1 ||
> > +	    frame->length != HDMI_AUDIO_INFOFRAME_SIZE)
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> > +/**
> > + * hdmi_audio_infoframe_check() - Check and check a HDMI audio infoframe
> > + * @frame: HDMI audio infoframe
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame)
> > +{
> > +	return hdmi_audio_infoframe_check_only(frame);
> > +}
> > +EXPORT_SYMBOL(hdmi_audio_infoframe_check);
> > +
> >  /**
> > - * hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
> > + * hdmi_audio_infoframe_pack_only() - write HDMI audio infoframe to binary buffer
> >   * @frame: HDMI audio infoframe
> >   * @buffer: destination buffer
> >   * @size: size of buffer
> > @@ -256,12 +401,17 @@ EXPORT_SYMBOL(hdmi_audio_infoframe_init);
> >   * Returns the number of bytes packed into the binary buffer or a negative
> >   * error code on failure.
> >   */
> > -ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> > -				  void *buffer, size_t size)
> > +ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
> > +				       void *buffer, size_t size)
> >  {
> >  	unsigned char channels;
> >  	u8 *ptr = buffer;
> >  	size_t length;
> > +	int ret;
> > +
> > +	ret = hdmi_audio_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> >  
> >  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
> >  
> > @@ -297,6 +447,36 @@ ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> >  
> >  	return length;
> >  }
> > +EXPORT_SYMBOL(hdmi_audio_infoframe_pack_only);
> > +
> > +/**
> > + * hdmi_audio_infoframe_pack() - Check and check a HDMI Audio infoframe,
> > + *                               and write it to binary buffer
> > + * @frame: HDMI Audio infoframe
> > + * @buffer: destination buffer
> > + * @size: size of buffer
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields, after which packs the information
> > + * contained in the @frame structure into a binary representation that
> > + * can be written into the corresponding controller registers. Also
> > + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> > + * specification.
> > + *
> > + * Returns the number of bytes packed into the binary buffer or a negative
> > + * error code on failure.
> > + */
> > +ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> > +				  void *buffer, size_t size)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_audio_infoframe_check(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return hdmi_audio_infoframe_pack_only(frame, buffer, size);
> > +}
> >  EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
> >  
> >  /**
> > @@ -319,6 +499,7 @@ int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame)
> >  	 * value
> >  	 */
> >  	frame->s3d_struct = HDMI_3D_STRUCTURE_INVALID;
> > +	frame->length = 4;
> >  
> >  	return 0;
> >  }
> > @@ -335,8 +516,42 @@ static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
> >  		return 4;
> >  }
> >  
> > +static int hdmi_vendor_infoframe_check_only(const struct hdmi_vendor_infoframe *frame)
> > +{
> > +	if (frame->type != HDMI_INFOFRAME_TYPE_VENDOR ||
> > +	    frame->version != 1 ||
> > +	    frame->oui != HDMI_IEEE_OUI)
> > +		return -EINVAL;
> > +
> > +	/* only one of those can be supplied */
> > +	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
> > +		return -EINVAL;
> > +
> > +	if (frame->length != hdmi_vendor_infoframe_length(frame))
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> >  /**
> > - * hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary buffer
> > + * hdmi_vendor_infoframe_check() - Check and check a HDMI vendor infoframe
> > + * @frame: HDMI infoframe
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame)
> > +{
> > +	frame->length = hdmi_vendor_infoframe_length(frame);
> > +
> > +	return hdmi_vendor_infoframe_check_only(frame);
> > +}
> > +EXPORT_SYMBOL(hdmi_vendor_infoframe_check);
> > +
> > +/**
> > + * hdmi_vendor_infoframe_pack_only() - write a HDMI vendor infoframe to binary buffer
> >   * @frame: HDMI infoframe
> >   * @buffer: destination buffer
> >   * @size: size of buffer
> > @@ -349,17 +564,16 @@ static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
> >   * Returns the number of bytes packed into the binary buffer or a negative
> >   * error code on failure.
> >   */
> > -ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> > -				 void *buffer, size_t size)
> > +ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
> > +					void *buffer, size_t size)
> >  {
> >  	u8 *ptr = buffer;
> >  	size_t length;
> > +	int ret;
> >  
> > -	/* only one of those can be supplied */
> > -	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
> > -		return -EINVAL;
> > -
> > -	frame->length = hdmi_vendor_infoframe_length(frame);
> > +	ret = hdmi_vendor_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> >  
> >  	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
> >  
> > @@ -394,24 +608,134 @@ ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> >  
> >  	return length;
> >  }
> > +EXPORT_SYMBOL(hdmi_vendor_infoframe_pack_only);
> > +
> > +/**
> > + * hdmi_vendor_infoframe_pack() - Check and check a HDMI Vendor infoframe,
> > + *                                and write it to binary buffer
> > + * @frame: HDMI Vendor infoframe
> > + * @buffer: destination buffer
> > + * @size: size of buffer
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields, after which packs the information
> > + * contained in the @frame structure into a binary representation that
> > + * can be written into the corresponding controller registers. Also
> > + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> > + * specification.
> > + *
> > + * Returns the number of bytes packed into the binary buffer or a negative
> > + * error code on failure.
> > + */
> > +ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> > +				   void *buffer, size_t size)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_vendor_infoframe_check(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return hdmi_vendor_infoframe_pack_only(frame, buffer, size);
> > +}
> >  EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);
> >  
> > +static int
> > +hdmi_vendor_any_infoframe_check_only(const union hdmi_vendor_any_infoframe *frame)
> > +{
> > +	if (frame->any.type != HDMI_INFOFRAME_TYPE_VENDOR ||
> > +	    frame->any.version != 1)
> > +		return -EINVAL;
> > +
> > +	return 0;
> > +}
> > +
> >  /*
> > - * hdmi_vendor_any_infoframe_pack() - write a vendor infoframe to binary buffer
> > + * hdmi_vendor_any_infoframe_check() - check and check a vendor infoframe
> > + */
> > +static int
> > +hdmi_vendor_any_infoframe_check(union hdmi_vendor_any_infoframe *frame)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_vendor_any_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	/* we only know about HDMI vendor infoframes */
> > +	if (frame->any.oui != HDMI_IEEE_OUI)
> > +		return -EINVAL;
> > +
> > +	return hdmi_vendor_infoframe_check(&frame->hdmi);
> > +}
> > +
> > +/*
> > + * hdmi_vendor_any_infoframe_pack_only() - write a vendor infoframe to binary buffer
> >   */
> >  static ssize_t
> > -hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> > -			   void *buffer, size_t size)
> > +hdmi_vendor_any_infoframe_pack_only(const union hdmi_vendor_any_infoframe *frame,
> > +				    void *buffer, size_t size)
> >  {
> > +	int ret;
> > +
> > +	ret = hdmi_vendor_any_infoframe_check_only(frame);
> > +	if (ret)
> > +		return ret;
> > +
> >  	/* we only know about HDMI vendor infoframes */
> >  	if (frame->any.oui != HDMI_IEEE_OUI)
> >  		return -EINVAL;
> >  
> > -	return hdmi_vendor_infoframe_pack(&frame->hdmi, buffer, size);
> > +	return hdmi_vendor_infoframe_pack_only(&frame->hdmi, buffer, size);
> > +}
> > +
> > +/*
> > + * hdmi_vendor_any_infoframe_pack() - check and check a vendor infoframe,
> > + *                                              and write it to binary buffer
> > + */
> > +static ssize_t
> > +hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> > +			       void *buffer, size_t size)
> > +{
> > +	int ret;
> > +
> > +	ret = hdmi_vendor_any_infoframe_check(frame);
> > +	if (ret)
> > +		return ret;
> > +
> > +	return hdmi_vendor_any_infoframe_pack_only(frame, buffer, size);
> > +}
> > +
> > +/**
> > + * hdmi_infoframe_check() - Check check a HDMI infoframe
> > + * @frame: HDMI infoframe
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields.
> > + *
> > + * Returns 0 on success or a negative error code on failure.
> > + */
> > +int
> > +hdmi_infoframe_check(union hdmi_infoframe *frame)
> > +{
> > +	switch (frame->any.type) {
> > +	case HDMI_INFOFRAME_TYPE_AVI:
> > +		return hdmi_avi_infoframe_check(&frame->avi);
> > +	case HDMI_INFOFRAME_TYPE_SPD:
> > +		return hdmi_spd_infoframe_check(&frame->spd);
> > +	case HDMI_INFOFRAME_TYPE_AUDIO:
> > +		return hdmi_audio_infoframe_check(&frame->audio);
> > +	case HDMI_INFOFRAME_TYPE_VENDOR:
> > +		return hdmi_vendor_any_infoframe_check(&frame->vendor);
> > +	default:
> > +		WARN(1, "Bad infoframe type %d\n", frame->any.type);
> > +		return -EINVAL;
> > +	}
> >  }
> > +EXPORT_SYMBOL(hdmi_infoframe_check);
> >  
> >  /**
> > - * hdmi_infoframe_pack() - write a HDMI infoframe to binary buffer
> > + * hdmi_infoframe_pack_only() - write a HDMI infoframe to binary buffer
> >   * @frame: HDMI infoframe
> >   * @buffer: destination buffer
> >   * @size: size of buffer
> > @@ -425,7 +749,56 @@ hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
> >   * error code on failure.
> >   */
> >  ssize_t
> > -hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size)
> > +hdmi_infoframe_pack_only(const union hdmi_infoframe *frame, void *buffer, size_t size)
> > +{
> > +	ssize_t length;
> > +
> > +	switch (frame->any.type) {
> > +	case HDMI_INFOFRAME_TYPE_AVI:
> > +		length = hdmi_avi_infoframe_pack_only(&frame->avi,
> > +						      buffer, size);
> > +		break;
> > +	case HDMI_INFOFRAME_TYPE_SPD:
> > +		length = hdmi_spd_infoframe_pack_only(&frame->spd,
> > +						      buffer, size);
> > +		break;
> > +	case HDMI_INFOFRAME_TYPE_AUDIO:
> > +		length = hdmi_audio_infoframe_pack_only(&frame->audio,
> > +							buffer, size);
> > +		break;
> > +	case HDMI_INFOFRAME_TYPE_VENDOR:
> > +		length = hdmi_vendor_any_infoframe_pack_only(&frame->vendor,
> > +							     buffer, size);
> > +		break;
> > +	default:
> > +		WARN(1, "Bad infoframe type %d\n", frame->any.type);
> > +		length = -EINVAL;
> > +	}
> > +
> > +	return length;
> > +}
> > +EXPORT_SYMBOL(hdmi_infoframe_pack_only);
> > +
> > +/**
> > + * hdmi_infoframe_pack() - Check check a HDMI infoframe,
> 
> Check check?
> 
> > + *                         and write it to binary buffer
> > + * @frame: HDMI infoframe
> > + * @buffer: destination buffer
> > + * @size: size of buffer
> > + *
> > + * Validates that the infoframe is consistent and updates derived fields
> > + * (eg. length) based on other fields, after which packs the information
> > + * contained in the @frame structure into a binary representation that
> > + * can be written into the corresponding controller registers. Also
> > + * computes the checksum as required by section 5.3.5 of the HDMI 1.4
> > + * specification.
> > + *
> > + * Returns the number of bytes packed into the binary buffer or a negative
> > + * error code on failure.
> > + */
> > +ssize_t
> > +hdmi_infoframe_pack(union hdmi_infoframe *frame,
> > +		    void *buffer, size_t size)
> >  {
> >  	ssize_t length;
> >  
> > diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
> > index bce1abb1fe57..c76b50a48e48 100644
> > --- a/include/linux/hdmi.h
> > +++ b/include/linux/hdmi.h
> > @@ -163,6 +163,9 @@ struct hdmi_avi_infoframe {
> >  int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame);
> >  ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
> >  				size_t size);
> > +ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
> > +				     void *buffer, size_t size);
> > +int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame);
> >  
> >  enum hdmi_spd_sdi {
> >  	HDMI_SPD_SDI_UNKNOWN,
> > @@ -194,6 +197,9 @@ int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
> >  			    const char *vendor, const char *product);
> >  ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
> >  				size_t size);
> > +ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
> > +				     void *buffer, size_t size);
> > +int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame);
> >  
> >  enum hdmi_audio_coding_type {
> >  	HDMI_AUDIO_CODING_TYPE_STREAM,
> > @@ -272,6 +278,9 @@ struct hdmi_audio_infoframe {
> >  int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
> >  ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
> >  				  void *buffer, size_t size);
> > +ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
> > +				       void *buffer, size_t size);
> > +int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame);
> >  
> >  enum hdmi_3d_structure {
> >  	HDMI_3D_STRUCTURE_INVALID = -1,
> > @@ -299,6 +308,9 @@ struct hdmi_vendor_infoframe {
> >  int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame);
> >  ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
> >  				   void *buffer, size_t size);
> > +ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
> > +					void *buffer, size_t size);
> > +int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame);
> >  
> >  union hdmi_vendor_any_infoframe {
> >  	struct {
> > @@ -330,8 +342,11 @@ union hdmi_infoframe {
> >  	struct hdmi_audio_infoframe audio;
> >  };
> >  
> > -ssize_t
> > -hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size);
> > +ssize_t hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer,
> > +			    size_t size);
> > +ssize_t hdmi_infoframe_pack_only(const union hdmi_infoframe *frame,
> > +				 void *buffer, size_t size);
> > +int hdmi_infoframe_check(union hdmi_infoframe *frame);
> >  int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
> >  			  const void *buffer, size_t size);
> >  void hdmi_infoframe_log(const char *level, struct device *dev,
> > 
> 
> Regards,
> 
> 	Hans

Patch

diff --git a/drivers/video/hdmi.c b/drivers/video/hdmi.c
index 53e7ee2c83fc..9507f668a569 100644
--- a/drivers/video/hdmi.c
+++ b/drivers/video/hdmi.c
@@ -68,8 +68,36 @@  int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame)
 }
 EXPORT_SYMBOL(hdmi_avi_infoframe_init);
 
+static int hdmi_avi_infoframe_check_only(const struct hdmi_avi_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_AVI ||
+	    frame->version != 2 ||
+	    frame->length != HDMI_AVI_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
- * hdmi_avi_infoframe_pack() - write HDMI AVI infoframe to binary buffer
+ * hdmi_avi_infoframe_check() - Check and check a HDMI AVI infoframe
+ * @frame: HDMI AVI infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame)
+{
+	return hdmi_avi_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_avi_infoframe_check);
+
+/**
+ * hdmi_avi_infoframe_pack_only() - write HDMI AVI infoframe to binary buffer
  * @frame: HDMI AVI infoframe
  * @buffer: destination buffer
  * @size: size of buffer
@@ -82,20 +110,22 @@  EXPORT_SYMBOL(hdmi_avi_infoframe_init);
  * Returns the number of bytes packed into the binary buffer or a negative
  * error code on failure.
  */
-ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
-				size_t size)
+ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
+				     void *buffer, size_t size)
 {
 	u8 *ptr = buffer;
 	size_t length;
+	int ret;
+
+	ret = hdmi_avi_infoframe_check_only(frame);
+	if (ret)
+		return ret;
 
 	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 
 	if (size < length)
 		return -ENOSPC;
 
-	if (frame->picture_aspect > HDMI_PICTURE_ASPECT_16_9)
-		return -EINVAL;
-
 	memset(buffer, 0, size);
 
 	ptr[0] = frame->type;
@@ -152,6 +182,36 @@  ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
 
 	return length;
 }
+EXPORT_SYMBOL(hdmi_avi_infoframe_pack_only);
+
+/**
+ * hdmi_avi_infoframe_pack() - Check and check a HDMI AVI infoframe,
+ *                             and write it to binary buffer
+ * @frame: HDMI AVI infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. Also
+ * computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame,
+				void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_avi_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_avi_infoframe_pack_only(frame, buffer, size);
+}
 EXPORT_SYMBOL(hdmi_avi_infoframe_pack);
 
 /**
@@ -178,8 +238,33 @@  int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
 }
 EXPORT_SYMBOL(hdmi_spd_infoframe_init);
 
+static int hdmi_spd_infoframe_check_only(const struct hdmi_spd_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_SPD ||
+	    frame->version != 1 ||
+	    frame->length != HDMI_SPD_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
- * hdmi_spd_infoframe_pack() - write HDMI SPD infoframe to binary buffer
+ * hdmi_spd_infoframe_check() - Check and check a HDMI SPD infoframe
+ * @frame: HDMI SPD infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame)
+{
+	return hdmi_spd_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_spd_infoframe_check);
+
+/**
+ * hdmi_spd_infoframe_pack_only() - write HDMI SPD infoframe to binary buffer
  * @frame: HDMI SPD infoframe
  * @buffer: destination buffer
  * @size: size of buffer
@@ -192,11 +277,16 @@  EXPORT_SYMBOL(hdmi_spd_infoframe_init);
  * Returns the number of bytes packed into the binary buffer or a negative
  * error code on failure.
  */
-ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
-				size_t size)
+ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
+				     void *buffer, size_t size)
 {
 	u8 *ptr = buffer;
 	size_t length;
+	int ret;
+
+	ret = hdmi_spd_infoframe_check_only(frame);
+	if (ret)
+		return ret;
 
 	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 
@@ -222,6 +312,36 @@  ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
 
 	return length;
 }
+EXPORT_SYMBOL(hdmi_spd_infoframe_pack_only);
+
+/**
+ * hdmi_spd_infoframe_pack() - Check and check a HDMI SPD infoframe,
+ *                             and write it to binary buffer
+ * @frame: HDMI SPD infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. Also
+ * computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame,
+				void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_spd_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_spd_infoframe_pack_only(frame, buffer, size);
+}
 EXPORT_SYMBOL(hdmi_spd_infoframe_pack);
 
 /**
@@ -242,8 +362,33 @@  int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame)
 }
 EXPORT_SYMBOL(hdmi_audio_infoframe_init);
 
+static int hdmi_audio_infoframe_check_only(const struct hdmi_audio_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_AUDIO ||
+	    frame->version != 1 ||
+	    frame->length != HDMI_AUDIO_INFOFRAME_SIZE)
+		return -EINVAL;
+
+	return 0;
+}
+
+/**
+ * hdmi_audio_infoframe_check() - Check and check a HDMI audio infoframe
+ * @frame: HDMI audio infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame)
+{
+	return hdmi_audio_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_audio_infoframe_check);
+
 /**
- * hdmi_audio_infoframe_pack() - write HDMI audio infoframe to binary buffer
+ * hdmi_audio_infoframe_pack_only() - write HDMI audio infoframe to binary buffer
  * @frame: HDMI audio infoframe
  * @buffer: destination buffer
  * @size: size of buffer
@@ -256,12 +401,17 @@  EXPORT_SYMBOL(hdmi_audio_infoframe_init);
  * Returns the number of bytes packed into the binary buffer or a negative
  * error code on failure.
  */
-ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
-				  void *buffer, size_t size)
+ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
+				       void *buffer, size_t size)
 {
 	unsigned char channels;
 	u8 *ptr = buffer;
 	size_t length;
+	int ret;
+
+	ret = hdmi_audio_infoframe_check_only(frame);
+	if (ret)
+		return ret;
 
 	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 
@@ -297,6 +447,36 @@  ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
 
 	return length;
 }
+EXPORT_SYMBOL(hdmi_audio_infoframe_pack_only);
+
+/**
+ * hdmi_audio_infoframe_pack() - Check and check a HDMI Audio infoframe,
+ *                               and write it to binary buffer
+ * @frame: HDMI Audio infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. Also
+ * computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
+				  void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_audio_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_audio_infoframe_pack_only(frame, buffer, size);
+}
 EXPORT_SYMBOL(hdmi_audio_infoframe_pack);
 
 /**
@@ -319,6 +499,7 @@  int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame)
 	 * value
 	 */
 	frame->s3d_struct = HDMI_3D_STRUCTURE_INVALID;
+	frame->length = 4;
 
 	return 0;
 }
@@ -335,8 +516,42 @@  static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
 		return 4;
 }
 
+static int hdmi_vendor_infoframe_check_only(const struct hdmi_vendor_infoframe *frame)
+{
+	if (frame->type != HDMI_INFOFRAME_TYPE_VENDOR ||
+	    frame->version != 1 ||
+	    frame->oui != HDMI_IEEE_OUI)
+		return -EINVAL;
+
+	/* only one of those can be supplied */
+	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
+		return -EINVAL;
+
+	if (frame->length != hdmi_vendor_infoframe_length(frame))
+		return -EINVAL;
+
+	return 0;
+}
+
 /**
- * hdmi_vendor_infoframe_pack() - write a HDMI vendor infoframe to binary buffer
+ * hdmi_vendor_infoframe_check() - Check and check a HDMI vendor infoframe
+ * @frame: HDMI infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame)
+{
+	frame->length = hdmi_vendor_infoframe_length(frame);
+
+	return hdmi_vendor_infoframe_check_only(frame);
+}
+EXPORT_SYMBOL(hdmi_vendor_infoframe_check);
+
+/**
+ * hdmi_vendor_infoframe_pack_only() - write a HDMI vendor infoframe to binary buffer
  * @frame: HDMI infoframe
  * @buffer: destination buffer
  * @size: size of buffer
@@ -349,17 +564,16 @@  static int hdmi_vendor_infoframe_length(const struct hdmi_vendor_infoframe *fram
  * Returns the number of bytes packed into the binary buffer or a negative
  * error code on failure.
  */
-ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
-				 void *buffer, size_t size)
+ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
+					void *buffer, size_t size)
 {
 	u8 *ptr = buffer;
 	size_t length;
+	int ret;
 
-	/* only one of those can be supplied */
-	if (frame->vic != 0 && frame->s3d_struct != HDMI_3D_STRUCTURE_INVALID)
-		return -EINVAL;
-
-	frame->length = hdmi_vendor_infoframe_length(frame);
+	ret = hdmi_vendor_infoframe_check_only(frame);
+	if (ret)
+		return ret;
 
 	length = HDMI_INFOFRAME_HEADER_SIZE + frame->length;
 
@@ -394,24 +608,134 @@  ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
 
 	return length;
 }
+EXPORT_SYMBOL(hdmi_vendor_infoframe_pack_only);
+
+/**
+ * hdmi_vendor_infoframe_pack() - Check and check a HDMI Vendor infoframe,
+ *                                and write it to binary buffer
+ * @frame: HDMI Vendor infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. Also
+ * computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
+				   void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_vendor_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_vendor_infoframe_pack_only(frame, buffer, size);
+}
 EXPORT_SYMBOL(hdmi_vendor_infoframe_pack);
 
+static int
+hdmi_vendor_any_infoframe_check_only(const union hdmi_vendor_any_infoframe *frame)
+{
+	if (frame->any.type != HDMI_INFOFRAME_TYPE_VENDOR ||
+	    frame->any.version != 1)
+		return -EINVAL;
+
+	return 0;
+}
+
 /*
- * hdmi_vendor_any_infoframe_pack() - write a vendor infoframe to binary buffer
+ * hdmi_vendor_any_infoframe_check() - check and check a vendor infoframe
+ */
+static int
+hdmi_vendor_any_infoframe_check(union hdmi_vendor_any_infoframe *frame)
+{
+	int ret;
+
+	ret = hdmi_vendor_any_infoframe_check_only(frame);
+	if (ret)
+		return ret;
+
+	/* we only know about HDMI vendor infoframes */
+	if (frame->any.oui != HDMI_IEEE_OUI)
+		return -EINVAL;
+
+	return hdmi_vendor_infoframe_check(&frame->hdmi);
+}
+
+/*
+ * hdmi_vendor_any_infoframe_pack_only() - write a vendor infoframe to binary buffer
  */
 static ssize_t
-hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
-			   void *buffer, size_t size)
+hdmi_vendor_any_infoframe_pack_only(const union hdmi_vendor_any_infoframe *frame,
+				    void *buffer, size_t size)
 {
+	int ret;
+
+	ret = hdmi_vendor_any_infoframe_check_only(frame);
+	if (ret)
+		return ret;
+
 	/* we only know about HDMI vendor infoframes */
 	if (frame->any.oui != HDMI_IEEE_OUI)
 		return -EINVAL;
 
-	return hdmi_vendor_infoframe_pack(&frame->hdmi, buffer, size);
+	return hdmi_vendor_infoframe_pack_only(&frame->hdmi, buffer, size);
+}
+
+/*
+ * hdmi_vendor_any_infoframe_pack() - check and check a vendor infoframe,
+ *                                              and write it to binary buffer
+ */
+static ssize_t
+hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
+			       void *buffer, size_t size)
+{
+	int ret;
+
+	ret = hdmi_vendor_any_infoframe_check(frame);
+	if (ret)
+		return ret;
+
+	return hdmi_vendor_any_infoframe_pack_only(frame, buffer, size);
+}
+
+/**
+ * hdmi_infoframe_check() - Check check a HDMI infoframe
+ * @frame: HDMI infoframe
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields.
+ *
+ * Returns 0 on success or a negative error code on failure.
+ */
+int
+hdmi_infoframe_check(union hdmi_infoframe *frame)
+{
+	switch (frame->any.type) {
+	case HDMI_INFOFRAME_TYPE_AVI:
+		return hdmi_avi_infoframe_check(&frame->avi);
+	case HDMI_INFOFRAME_TYPE_SPD:
+		return hdmi_spd_infoframe_check(&frame->spd);
+	case HDMI_INFOFRAME_TYPE_AUDIO:
+		return hdmi_audio_infoframe_check(&frame->audio);
+	case HDMI_INFOFRAME_TYPE_VENDOR:
+		return hdmi_vendor_any_infoframe_check(&frame->vendor);
+	default:
+		WARN(1, "Bad infoframe type %d\n", frame->any.type);
+		return -EINVAL;
+	}
 }
+EXPORT_SYMBOL(hdmi_infoframe_check);
 
 /**
- * hdmi_infoframe_pack() - write a HDMI infoframe to binary buffer
+ * hdmi_infoframe_pack_only() - write a HDMI infoframe to binary buffer
  * @frame: HDMI infoframe
  * @buffer: destination buffer
  * @size: size of buffer
@@ -425,7 +749,56 @@  hdmi_vendor_any_infoframe_pack(union hdmi_vendor_any_infoframe *frame,
  * error code on failure.
  */
 ssize_t
-hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size)
+hdmi_infoframe_pack_only(const union hdmi_infoframe *frame, void *buffer, size_t size)
+{
+	ssize_t length;
+
+	switch (frame->any.type) {
+	case HDMI_INFOFRAME_TYPE_AVI:
+		length = hdmi_avi_infoframe_pack_only(&frame->avi,
+						      buffer, size);
+		break;
+	case HDMI_INFOFRAME_TYPE_SPD:
+		length = hdmi_spd_infoframe_pack_only(&frame->spd,
+						      buffer, size);
+		break;
+	case HDMI_INFOFRAME_TYPE_AUDIO:
+		length = hdmi_audio_infoframe_pack_only(&frame->audio,
+							buffer, size);
+		break;
+	case HDMI_INFOFRAME_TYPE_VENDOR:
+		length = hdmi_vendor_any_infoframe_pack_only(&frame->vendor,
+							     buffer, size);
+		break;
+	default:
+		WARN(1, "Bad infoframe type %d\n", frame->any.type);
+		length = -EINVAL;
+	}
+
+	return length;
+}
+EXPORT_SYMBOL(hdmi_infoframe_pack_only);
+
+/**
+ * hdmi_infoframe_pack() - Check check a HDMI infoframe,
+ *                         and write it to binary buffer
+ * @frame: HDMI infoframe
+ * @buffer: destination buffer
+ * @size: size of buffer
+ *
+ * Validates that the infoframe is consistent and updates derived fields
+ * (eg. length) based on other fields, after which packs the information
+ * contained in the @frame structure into a binary representation that
+ * can be written into the corresponding controller registers. Also
+ * computes the checksum as required by section 5.3.5 of the HDMI 1.4
+ * specification.
+ *
+ * Returns the number of bytes packed into the binary buffer or a negative
+ * error code on failure.
+ */
+ssize_t
+hdmi_infoframe_pack(union hdmi_infoframe *frame,
+		    void *buffer, size_t size)
 {
 	ssize_t length;
 
diff --git a/include/linux/hdmi.h b/include/linux/hdmi.h
index bce1abb1fe57..c76b50a48e48 100644
--- a/include/linux/hdmi.h
+++ b/include/linux/hdmi.h
@@ -163,6 +163,9 @@  struct hdmi_avi_infoframe {
 int hdmi_avi_infoframe_init(struct hdmi_avi_infoframe *frame);
 ssize_t hdmi_avi_infoframe_pack(struct hdmi_avi_infoframe *frame, void *buffer,
 				size_t size);
+ssize_t hdmi_avi_infoframe_pack_only(const struct hdmi_avi_infoframe *frame,
+				     void *buffer, size_t size);
+int hdmi_avi_infoframe_check(struct hdmi_avi_infoframe *frame);
 
 enum hdmi_spd_sdi {
 	HDMI_SPD_SDI_UNKNOWN,
@@ -194,6 +197,9 @@  int hdmi_spd_infoframe_init(struct hdmi_spd_infoframe *frame,
 			    const char *vendor, const char *product);
 ssize_t hdmi_spd_infoframe_pack(struct hdmi_spd_infoframe *frame, void *buffer,
 				size_t size);
+ssize_t hdmi_spd_infoframe_pack_only(const struct hdmi_spd_infoframe *frame,
+				     void *buffer, size_t size);
+int hdmi_spd_infoframe_check(struct hdmi_spd_infoframe *frame);
 
 enum hdmi_audio_coding_type {
 	HDMI_AUDIO_CODING_TYPE_STREAM,
@@ -272,6 +278,9 @@  struct hdmi_audio_infoframe {
 int hdmi_audio_infoframe_init(struct hdmi_audio_infoframe *frame);
 ssize_t hdmi_audio_infoframe_pack(struct hdmi_audio_infoframe *frame,
 				  void *buffer, size_t size);
+ssize_t hdmi_audio_infoframe_pack_only(const struct hdmi_audio_infoframe *frame,
+				       void *buffer, size_t size);
+int hdmi_audio_infoframe_check(struct hdmi_audio_infoframe *frame);
 
 enum hdmi_3d_structure {
 	HDMI_3D_STRUCTURE_INVALID = -1,
@@ -299,6 +308,9 @@  struct hdmi_vendor_infoframe {
 int hdmi_vendor_infoframe_init(struct hdmi_vendor_infoframe *frame);
 ssize_t hdmi_vendor_infoframe_pack(struct hdmi_vendor_infoframe *frame,
 				   void *buffer, size_t size);
+ssize_t hdmi_vendor_infoframe_pack_only(const struct hdmi_vendor_infoframe *frame,
+					void *buffer, size_t size);
+int hdmi_vendor_infoframe_check(struct hdmi_vendor_infoframe *frame);
 
 union hdmi_vendor_any_infoframe {
 	struct {
@@ -330,8 +342,11 @@  union hdmi_infoframe {
 	struct hdmi_audio_infoframe audio;
 };
 
-ssize_t
-hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer, size_t size);
+ssize_t hdmi_infoframe_pack(union hdmi_infoframe *frame, void *buffer,
+			    size_t size);
+ssize_t hdmi_infoframe_pack_only(const union hdmi_infoframe *frame,
+				 void *buffer, size_t size);
+int hdmi_infoframe_check(union hdmi_infoframe *frame);
 int hdmi_infoframe_unpack(union hdmi_infoframe *frame,
 			  const void *buffer, size_t size);
 void hdmi_infoframe_log(const char *level, struct device *dev,