diff mbox

[v1,4/5,media] stm32-dcmi: set default format at open()

Message ID 1501236302-18097-5-git-send-email-hugues.fruchet@st.com (mailing list archive)
State New, archived
Headers show

Commit Message

Hugues FRUCHET July 28, 2017, 10:05 a.m. UTC 
Ensure that we start with default pixel format and resolution
when opening a new instance.

Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
---
 drivers/media/platform/stm32/stm32-dcmi.c | 49 ++++++++++++++++++-------------
 1 file changed, 28 insertions(+), 21 deletions(-)

Comments

Hans Verkuil Aug. 4, 2017, noon UTC | #1 
On 28/07/17 12:05, Hugues Fruchet wrote:
> Ensure that we start with default pixel format and resolution
> when opening a new instance.

Why? The format is persistent in V4L2 and (re)opening the video device
shouldn't change the format.

Suppose you use v4l2-ctl to set up a format. E.g. v4l2-ctl -v width=320,height-240.
Now run v4l2-ctl -V to get the format and with this code it would suddenly be
back to the default!

You set up the default format in the dcmi_graph_notify_complete, but after that
it is only changed if userspace explicitly requests it.

Regards,

	Hans

> 
> Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
> ---
>  drivers/media/platform/stm32/stm32-dcmi.c | 49 ++++++++++++++++++-------------
>  1 file changed, 28 insertions(+), 21 deletions(-)
> 
> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
> index 4733d1f..2be56b6 100644
> --- a/drivers/media/platform/stm32/stm32-dcmi.c
> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
> @@ -890,6 +890,28 @@ static int dcmi_enum_frameintervals(struct file *file, void *fh,
>  	return 0;
>  }
>  
> +static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
> +{
> +	struct v4l2_format f = {
> +		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
> +		.fmt.pix = {
> +			.width		= CIF_WIDTH,
> +			.height		= CIF_HEIGHT,
> +			.field		= V4L2_FIELD_NONE,
> +			.pixelformat	= dcmi->sd_formats[0]->fourcc,
> +		},
> +	};
> +	int ret;
> +
> +	ret = dcmi_try_fmt(dcmi, &f, NULL);
> +	if (ret)
> +		return ret;
> +	dcmi->sd_format = dcmi->sd_formats[0];
> +	dcmi->fmt = f;
> +
> +	return 0;
> +}
> +
>  static const struct of_device_id stm32_dcmi_of_match[] = {
>  	{ .compatible = "st,stm32-dcmi"},
>  	{ /* end node */ },
> @@ -916,7 +938,13 @@ static int dcmi_open(struct file *file)
>  	if (ret < 0 && ret != -ENOIOCTLCMD)
>  		goto fh_rel;
>  
> +	ret = dcmi_set_default_fmt(dcmi);
> +	if (ret)
> +		goto power_off;
> +
>  	ret = dcmi_set_fmt(dcmi, &dcmi->fmt);
> +
> +power_off:
>  	if (ret)
>  		v4l2_subdev_call(sd, core, s_power, 0);
>  fh_rel:
> @@ -991,27 +1019,6 @@ static int dcmi_release(struct file *file)
>  	.read		= vb2_fop_read,
>  };
>  
> -static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
> -{
> -	struct v4l2_format f = {
> -		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
> -		.fmt.pix = {
> -			.width		= CIF_WIDTH,
> -			.height		= CIF_HEIGHT,
> -			.field		= V4L2_FIELD_NONE,
> -			.pixelformat	= dcmi->sd_formats[0]->fourcc,
> -		},
> -	};
> -	int ret;
> -
> -	ret = dcmi_try_fmt(dcmi, &f, NULL);
> -	if (ret)
> -		return ret;
> -	dcmi->sd_format = dcmi->sd_formats[0];
> -	dcmi->fmt = f;
> -	return 0;
> -}
> -
>  static const struct dcmi_format dcmi_formats[] = {
>  	{
>  		.fourcc = V4L2_PIX_FMT_RGB565,
>
Hugues FRUCHET Aug. 21, 2017, 10:20 a.m. UTC | #2 
On 08/04/2017 02:00 PM, Hans Verkuil wrote:
> On 28/07/17 12:05, Hugues Fruchet wrote:
>> Ensure that we start with default pixel format and resolution
>> when opening a new instance.
> 
> Why? The format is persistent in V4L2 and (re)opening the video device
> shouldn't change the format.
> 
> Suppose you use v4l2-ctl to set up a format. E.g. v4l2-ctl -v width=320,height-240.
> Now run v4l2-ctl -V to get the format and with this code it would suddenly be
> back to the default!
> 
> You set up the default format in the dcmi_graph_notify_complete, but after that
> it is only changed if userspace explicitly requests it.
> 
> Regards,
> 
> 	Hans
> 

Thanks Hans, I didn't catch this before, thanks for explanation.

>>
>> Signed-off-by: Hugues Fruchet <hugues.fruchet@st.com>
>> ---
>>   drivers/media/platform/stm32/stm32-dcmi.c | 49 ++++++++++++++++++-------------
>>   1 file changed, 28 insertions(+), 21 deletions(-)
>>
>> diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
>> index 4733d1f..2be56b6 100644
>> --- a/drivers/media/platform/stm32/stm32-dcmi.c
>> +++ b/drivers/media/platform/stm32/stm32-dcmi.c
>> @@ -890,6 +890,28 @@ static int dcmi_enum_frameintervals(struct file *file, void *fh,
>>   	return 0;
>>   }
>>   
>> +static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
>> +{
>> +	struct v4l2_format f = {
>> +		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
>> +		.fmt.pix = {
>> +			.width		= CIF_WIDTH,
>> +			.height		= CIF_HEIGHT,
>> +			.field		= V4L2_FIELD_NONE,
>> +			.pixelformat	= dcmi->sd_formats[0]->fourcc,
>> +		},
>> +	};
>> +	int ret;
>> +
>> +	ret = dcmi_try_fmt(dcmi, &f, NULL);
>> +	if (ret)
>> +		return ret;
>> +	dcmi->sd_format = dcmi->sd_formats[0];
>> +	dcmi->fmt = f;
>> +
>> +	return 0;
>> +}
>> +
>>   static const struct of_device_id stm32_dcmi_of_match[] = {
>>   	{ .compatible = "st,stm32-dcmi"},
>>   	{ /* end node */ },
>> @@ -916,7 +938,13 @@ static int dcmi_open(struct file *file)
>>   	if (ret < 0 && ret != -ENOIOCTLCMD)
>>   		goto fh_rel;
>>   
>> +	ret = dcmi_set_default_fmt(dcmi);
>> +	if (ret)
>> +		goto power_off;
>> +
>>   	ret = dcmi_set_fmt(dcmi, &dcmi->fmt);
>> +
>> +power_off:
>>   	if (ret)
>>   		v4l2_subdev_call(sd, core, s_power, 0);
>>   fh_rel:
>> @@ -991,27 +1019,6 @@ static int dcmi_release(struct file *file)
>>   	.read		= vb2_fop_read,
>>   };
>>   
>> -static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
>> -{
>> -	struct v4l2_format f = {
>> -		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
>> -		.fmt.pix = {
>> -			.width		= CIF_WIDTH,
>> -			.height		= CIF_HEIGHT,
>> -			.field		= V4L2_FIELD_NONE,
>> -			.pixelformat	= dcmi->sd_formats[0]->fourcc,
>> -		},
>> -	};
>> -	int ret;
>> -
>> -	ret = dcmi_try_fmt(dcmi, &f, NULL);
>> -	if (ret)
>> -		return ret;
>> -	dcmi->sd_format = dcmi->sd_formats[0];
>> -	dcmi->fmt = f;
>> -	return 0;
>> -}
>> -
>>   static const struct dcmi_format dcmi_formats[] = {
>>   	{
>>   		.fourcc = V4L2_PIX_FMT_RGB565,
>>
>
diff mbox

Patch

diff --git a/drivers/media/platform/stm32/stm32-dcmi.c b/drivers/media/platform/stm32/stm32-dcmi.c
index 4733d1f..2be56b6 100644
--- a/drivers/media/platform/stm32/stm32-dcmi.c
+++ b/drivers/media/platform/stm32/stm32-dcmi.c
@@ -890,6 +890,28 @@  static int dcmi_enum_frameintervals(struct file *file, void *fh,
 	return 0;
 }
 
+static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
+{
+	struct v4l2_format f = {
+		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
+		.fmt.pix = {
+			.width		= CIF_WIDTH,
+			.height		= CIF_HEIGHT,
+			.field		= V4L2_FIELD_NONE,
+			.pixelformat	= dcmi->sd_formats[0]->fourcc,
+		},
+	};
+	int ret;
+
+	ret = dcmi_try_fmt(dcmi, &f, NULL);
+	if (ret)
+		return ret;
+	dcmi->sd_format = dcmi->sd_formats[0];
+	dcmi->fmt = f;
+
+	return 0;
+}
+
 static const struct of_device_id stm32_dcmi_of_match[] = {
 	{ .compatible = "st,stm32-dcmi"},
 	{ /* end node */ },
@@ -916,7 +938,13 @@  static int dcmi_open(struct file *file)
 	if (ret < 0 && ret != -ENOIOCTLCMD)
 		goto fh_rel;
 
+	ret = dcmi_set_default_fmt(dcmi);
+	if (ret)
+		goto power_off;
+
 	ret = dcmi_set_fmt(dcmi, &dcmi->fmt);
+
+power_off:
 	if (ret)
 		v4l2_subdev_call(sd, core, s_power, 0);
 fh_rel:
@@ -991,27 +1019,6 @@  static int dcmi_release(struct file *file)
 	.read		= vb2_fop_read,
 };
 
-static int dcmi_set_default_fmt(struct stm32_dcmi *dcmi)
-{
-	struct v4l2_format f = {
-		.type = V4L2_BUF_TYPE_VIDEO_CAPTURE,
-		.fmt.pix = {
-			.width		= CIF_WIDTH,
-			.height		= CIF_HEIGHT,
-			.field		= V4L2_FIELD_NONE,
-			.pixelformat	= dcmi->sd_formats[0]->fourcc,
-		},
-	};
-	int ret;
-
-	ret = dcmi_try_fmt(dcmi, &f, NULL);
-	if (ret)
-		return ret;
-	dcmi->sd_format = dcmi->sd_formats[0];
-	dcmi->fmt = f;
-	return 0;
-}
-
 static const struct dcmi_format dcmi_formats[] = {
 	{
 		.fourcc = V4L2_PIX_FMT_RGB565,