diff mbox

[5/5] drm/i915: Add YCBCR 4:2:0 support for LSPCON

Message ID 1510672646-29918-6-git-send-email-shashank.sharma@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

Sharma, Shashank Nov. 14, 2017, 3:17 p.m. UTC
LSPCON chips are capable of generating YCBCR 4:2:0 outputs, if asked
nicely :). In order to generate YCBCR 4:2:0 outputs, a source must:
- send YCBCR 4:4:4 signals to LSPCON
- program color space as 4:2:0 in AVI infoframes

This will indicate LSPCON FW to start scaling down from YCBCR 4:4:4
and generate YCBCR 4:2:0 output. Unlike HDMI 2.0 native case, as the
scaling is done by LSPCON device, we need not to reserve a scaler for
4:2:0 outputs.

Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
---
 drivers/gpu/drm/i915/i915_reg.h      |  2 ++
 drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
 drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++----
 drivers/gpu/drm/i915/intel_dp.c      |  7 ++++++-
 drivers/gpu/drm/i915/intel_drv.h     |  2 ++
 drivers/gpu/drm/i915/intel_lspcon.c  | 22 ++++++++++++++++++++++
 6 files changed, 51 insertions(+), 5 deletions(-)

Comments

Ville Syrjala Nov. 14, 2017, 3:39 p.m. UTC | #1
On Tue, Nov 14, 2017 at 08:47:26PM +0530, Shashank Sharma wrote:
> LSPCON chips are capable of generating YCBCR 4:2:0 outputs, if asked
> nicely :). In order to generate YCBCR 4:2:0 outputs, a source must:
> - send YCBCR 4:4:4 signals to LSPCON
> - program color space as 4:2:0 in AVI infoframes
> 
> This will indicate LSPCON FW to start scaling down from YCBCR 4:4:4
> and generate YCBCR 4:2:0 output. Unlike HDMI 2.0 native case, as the
> scaling is done by LSPCON device, we need not to reserve a scaler for
> 4:2:0 outputs.
> 
> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  2 ++
>  drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>  drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++----
>  drivers/gpu/drm/i915/intel_dp.c      |  7 ++++++-
>  drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>  drivers/gpu/drm/i915/intel_lspcon.c  | 22 ++++++++++++++++++++++
>  6 files changed, 51 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f0f8f60..ea6ef5e 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8495,6 +8495,8 @@ enum skl_power_gate {
>  #define TRANS_MSA_MISC(tran) _MMIO_TRANS2(tran, _TRANSA_MSA_MISC)
>  
>  #define  TRANS_MSA_SYNC_CLK		(1<<0)
> +#define  TRANS_MSA_SAMPLING_444        (2<<1)
> +#define  TRANS_MSA_CLRSP_YCBCR		(2<<3)
>  #define  TRANS_MSA_6_BPC		(0<<5)
>  #define  TRANS_MSA_8_BPC		(1<<5)
>  #define  TRANS_MSA_10_BPC		(2<<5)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 9e2ab02..3fd839d 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1499,6 +1499,14 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
>  		break;
>  	}
>  
> +	/*
> +	 * To get YCBCR 420 output from LSPCON, we should send YCBCR 444
> +	 * signals. And as per DP 1.2 spec section 2.3.4.3 while sending
> +	 * YCBCR 444 signals we should program MSA MISC1/0 fields with
> +	 * colorspace information.
> +	 */
> +	if (crtc_state->lspcon_active && crtc_state->ycbcr420)

I think it would be much cleaner if we just set
crtc_state->ycbcr444=true here instead of crtc_state->ycbcr420=true,
and then have a separate flag to control the 444->420 downsampling in
the DP device/LSPCON. Not quite sure what we should call that, maybe just
somehting like crtc_state->ycbcr444_to_ycbcr420. That way you'll pretty
much have implemented ycbcr444 support for us apart from the uapi to
flip it on.

Looks like state readout support is also missing from this patch.

> +		temp |= TRANS_MSA_SAMPLING_444 | TRANS_MSA_CLRSP_YCBCR;
>  	I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 737de25..787119b 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4638,7 +4638,8 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>  	 */
>  	need_scaling = src_w != dst_w || src_h != dst_h;
>  
> -	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX)
> +	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX &&
> +		!crtc_state->lspcon_active)
>  		need_scaling = true;
>  
>  	/*
> @@ -8133,9 +8134,15 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>  			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
>  
>  		if (config->ycbcr420) {
> -			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV |
> -				PIPEMISC_YUV420_ENABLE |
> -				PIPEMISC_YUV420_MODE_FULL_BLEND;
> +			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV;
> +			/*
> +			 * LSPCON doesn't need scaling/blending to be done in
> +			 * pipe. It just needs YCBCR444 input and proper AVI
> +			 * infoframes for 4:2:0 output enabling.
> +			 */
> +			if (!config->lspcon_active)
> +				val |= PIPEMISC_YUV420_ENABLE |
> +				       PIPEMISC_YUV420_MODE_FULL_BLEND;
>  		}
>  
>  		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index fa9e5e6..1d4b669 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1657,8 +1657,13 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>  						    intel_dp->max_link_rate);
>  
>  	/* LSPCON needs special handling to drive YCBCR420 outputs */
> -	if (lspcon->active)
> +	if (lspcon->active) {
> +		struct drm_connector *connector = &intel_connector->base;
> +
>  		pipe_config->lspcon_active = true;
> +		pipe_config->ycbcr420 = lspcon_ycbcr420_config(connector,
> +							       pipe_config);
> +	}
>  
>  	/* No common link rates between source and sink */
>  	WARN_ON(common_len <= 0);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a468dd6..f271967 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -2047,6 +2047,8 @@ void lspcon_set_infoframes(struct drm_encoder *encoder,
>  			   const struct drm_connector_state *conn_state);
>  bool lspcon_infoframe_enabled(struct drm_encoder *encoder,
>  			      const struct intel_crtc_state *pipe_config);
> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
> +			     struct intel_crtc_state *config);
>  
>  /* intel_pipe_crc.c */
>  int intel_pipe_crc_create(struct drm_minor *minor);
> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> index 77f0687..ca77f50 100644
> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> @@ -180,6 +180,26 @@ static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
>  	return true;
>  }
>  
> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
> +			     struct intel_crtc_state *config)
> +{
> +	struct drm_display_info *info = &connector->display_info;
> +	struct drm_display_mode *mode = &config->base.adjusted_mode;
> +
> +	if (drm_mode_is_420_only(info, mode)) {
> +
> +		if (!connector->ycbcr_420_allowed) {
> +			DRM_ERROR("Platform doesn't support YCBCR420 output\n");
> +			return false;
> +		}
> +
> +		config->port_clock /= 2;
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
>  static bool lspcon_probe(struct intel_lspcon *lspcon)
>  {
>  	int retry;
> @@ -516,6 +536,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>  	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
>  	struct drm_device *dev = intel_dig_port->base.base.dev;
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> +	struct drm_connector *connector = &dp->attached_connector->base;
>  
>  	if (!HAS_LSPCON(dev_priv)) {
>  		DRM_ERROR("LSPCON is not supported on this platform\n");
> @@ -540,6 +561,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>  		return false;
>  	}
>  
> +	connector->ycbcr_420_allowed = true;
>  	lspcon->active = true;
>  	DRM_DEBUG_KMS("Success: LSPCON init\n");
>  	return true;
> -- 
> 2.7.4
Maarten Lankhorst Dec. 18, 2017, 7:23 p.m. UTC | #2
Op 14-11-17 om 16:17 schreef Shashank Sharma:
> LSPCON chips are capable of generating YCBCR 4:2:0 outputs, if asked
> nicely :). In order to generate YCBCR 4:2:0 outputs, a source must:
> - send YCBCR 4:4:4 signals to LSPCON
> - program color space as 4:2:0 in AVI infoframes
>
> This will indicate LSPCON FW to start scaling down from YCBCR 4:4:4
> and generate YCBCR 4:2:0 output. Unlike HDMI 2.0 native case, as the
> scaling is done by LSPCON device, we need not to reserve a scaler for
> 4:2:0 outputs.
>
> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
> ---
>  drivers/gpu/drm/i915/i915_reg.h      |  2 ++
>  drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>  drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++----
>  drivers/gpu/drm/i915/intel_dp.c      |  7 ++++++-
>  drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>  drivers/gpu/drm/i915/intel_lspcon.c  | 22 ++++++++++++++++++++++
>  6 files changed, 51 insertions(+), 5 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
> index f0f8f60..ea6ef5e 100644
> --- a/drivers/gpu/drm/i915/i915_reg.h
> +++ b/drivers/gpu/drm/i915/i915_reg.h
> @@ -8495,6 +8495,8 @@ enum skl_power_gate {
>  #define TRANS_MSA_MISC(tran) _MMIO_TRANS2(tran, _TRANSA_MSA_MISC)
>  
>  #define  TRANS_MSA_SYNC_CLK		(1<<0)
> +#define  TRANS_MSA_SAMPLING_444        (2<<1)
> +#define  TRANS_MSA_CLRSP_YCBCR		(2<<3)
>  #define  TRANS_MSA_6_BPC		(0<<5)
>  #define  TRANS_MSA_8_BPC		(1<<5)
>  #define  TRANS_MSA_10_BPC		(2<<5)
> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> index 9e2ab02..3fd839d 100644
> --- a/drivers/gpu/drm/i915/intel_ddi.c
> +++ b/drivers/gpu/drm/i915/intel_ddi.c
> @@ -1499,6 +1499,14 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
>  		break;
>  	}
>  
> +	/*
> +	 * To get YCBCR 420 output from LSPCON, we should send YCBCR 444
> +	 * signals. And as per DP 1.2 spec section 2.3.4.3 while sending
> +	 * YCBCR 444 signals we should program MSA MISC1/0 fields with
> +	 * colorspace information.
> +	 */
> +	if (crtc_state->lspcon_active && crtc_state->ycbcr420)
> +		temp |= TRANS_MSA_SAMPLING_444 | TRANS_MSA_CLRSP_YCBCR;
>  	I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
>  }
>  
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index 737de25..787119b 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4638,7 +4638,8 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>  	 */
>  	need_scaling = src_w != dst_w || src_h != dst_h;
>  
> -	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX)
> +	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX &&
> +		!crtc_state->lspcon_active)
>  		need_scaling = true;
>  
>  	/*
> @@ -8133,9 +8134,15 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>  			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
>  
>  		if (config->ycbcr420) {
> -			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV |
> -				PIPEMISC_YUV420_ENABLE |
> -				PIPEMISC_YUV420_MODE_FULL_BLEND;
> +			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV;
> +			/*
> +			 * LSPCON doesn't need scaling/blending to be done in
> +			 * pipe. It just needs YCBCR444 input and proper AVI
> +			 * infoframes for 4:2:0 output enabling.
> +			 */
> +			if (!config->lspcon_active)
> +				val |= PIPEMISC_YUV420_ENABLE |
> +				       PIPEMISC_YUV420_MODE_FULL_BLEND;
>  		}
>  
>  		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index fa9e5e6..1d4b669 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -1657,8 +1657,13 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>  						    intel_dp->max_link_rate);
>  
>  	/* LSPCON needs special handling to drive YCBCR420 outputs */
> -	if (lspcon->active)
> +	if (lspcon->active) {
> +		struct drm_connector *connector = &intel_connector->base;
> +
>  		pipe_config->lspcon_active = true;
> +		pipe_config->ycbcr420 = lspcon_ycbcr420_config(connector,
> +							       pipe_config);
> +	}
>  
>  	/* No common link rates between source and sink */
>  	WARN_ON(common_len <= 0);
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index a468dd6..f271967 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -2047,6 +2047,8 @@ void lspcon_set_infoframes(struct drm_encoder *encoder,
>  			   const struct drm_connector_state *conn_state);
>  bool lspcon_infoframe_enabled(struct drm_encoder *encoder,
>  			      const struct intel_crtc_state *pipe_config);
> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
> +			     struct intel_crtc_state *config);
>  
>  /* intel_pipe_crc.c */
>  int intel_pipe_crc_create(struct drm_minor *minor);
> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
> index 77f0687..ca77f50 100644
> --- a/drivers/gpu/drm/i915/intel_lspcon.c
> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
> @@ -180,6 +180,26 @@ static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
>  	return true;
>  }
>  
> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
> +			     struct intel_crtc_state *config)
> +{
> +	struct drm_display_info *info = &connector->display_info;
> +	struct drm_display_mode *mode = &config->base.adjusted_mode;
> +
> +	if (drm_mode_is_420_only(info, mode)) {
> +
> +		if (!connector->ycbcr_420_allowed) {
> +			DRM_ERROR("Platform doesn't support YCBCR420 output\n");
> +			return false;
> +		}
Seems to be always true if lspcon->active is true?
> +		config->port_clock /= 2;
> +		return true;
> +	}
> +
> +	return false;
> +}
> +
>  static bool lspcon_probe(struct intel_lspcon *lspcon)
>  {
>  	int retry;
> @@ -516,6 +536,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>  	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
>  	struct drm_device *dev = intel_dig_port->base.base.dev;
>  	struct drm_i915_private *dev_priv = to_i915(dev);
> +	struct drm_connector *connector = &dp->attached_connector->base;
>  
>  	if (!HAS_LSPCON(dev_priv)) {
>  		DRM_ERROR("LSPCON is not supported on this platform\n");
> @@ -540,6 +561,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>  		return false;
>  	}
>  
> +	connector->ycbcr_420_allowed = true;
Is this flag different from lspcon->active?
>  	lspcon->active = true;
>  	DRM_DEBUG_KMS("Success: LSPCON init\n");
>  	return true;

Comments from Ville still apply too. The pipe is set to ycbcr mode, so it makes more sense to have a ycbcr444 flag or something, and a separate flag to downconvert lspcon.

It would be really nice if we could set the ycbcr444 flag in hw readout, and intel_pipe_config_compare. This way we know the sw mode matches the hw mode. :)

~Maarten
Sharma, Shashank Dec. 20, 2017, 5:01 a.m. UTC | #3
Thanks for the review Maarten,

My comments inline.

Regards
Shashank
On 12/19/2017 12:53 AM, Maarten Lankhorst wrote:
> Op 14-11-17 om 16:17 schreef Shashank Sharma:
>> LSPCON chips are capable of generating YCBCR 4:2:0 outputs, if asked
>> nicely :). In order to generate YCBCR 4:2:0 outputs, a source must:
>> - send YCBCR 4:4:4 signals to LSPCON
>> - program color space as 4:2:0 in AVI infoframes
>>
>> This will indicate LSPCON FW to start scaling down from YCBCR 4:4:4
>> and generate YCBCR 4:2:0 output. Unlike HDMI 2.0 native case, as the
>> scaling is done by LSPCON device, we need not to reserve a scaler for
>> 4:2:0 outputs.
>>
>> Signed-off-by: Shashank Sharma <shashank.sharma@intel.com>
>> ---
>>   drivers/gpu/drm/i915/i915_reg.h      |  2 ++
>>   drivers/gpu/drm/i915/intel_ddi.c     |  8 ++++++++
>>   drivers/gpu/drm/i915/intel_display.c | 15 +++++++++++----
>>   drivers/gpu/drm/i915/intel_dp.c      |  7 ++++++-
>>   drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>>   drivers/gpu/drm/i915/intel_lspcon.c  | 22 ++++++++++++++++++++++
>>   6 files changed, 51 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
>> index f0f8f60..ea6ef5e 100644
>> --- a/drivers/gpu/drm/i915/i915_reg.h
>> +++ b/drivers/gpu/drm/i915/i915_reg.h
>> @@ -8495,6 +8495,8 @@ enum skl_power_gate {
>>   #define TRANS_MSA_MISC(tran) _MMIO_TRANS2(tran, _TRANSA_MSA_MISC)
>>   
>>   #define  TRANS_MSA_SYNC_CLK		(1<<0)
>> +#define  TRANS_MSA_SAMPLING_444        (2<<1)
>> +#define  TRANS_MSA_CLRSP_YCBCR		(2<<3)
>>   #define  TRANS_MSA_6_BPC		(0<<5)
>>   #define  TRANS_MSA_8_BPC		(1<<5)
>>   #define  TRANS_MSA_10_BPC		(2<<5)
>> diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
>> index 9e2ab02..3fd839d 100644
>> --- a/drivers/gpu/drm/i915/intel_ddi.c
>> +++ b/drivers/gpu/drm/i915/intel_ddi.c
>> @@ -1499,6 +1499,14 @@ void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
>>   		break;
>>   	}
>>   
>> +	/*
>> +	 * To get YCBCR 420 output from LSPCON, we should send YCBCR 444
>> +	 * signals. And as per DP 1.2 spec section 2.3.4.3 while sending
>> +	 * YCBCR 444 signals we should program MSA MISC1/0 fields with
>> +	 * colorspace information.
>> +	 */
>> +	if (crtc_state->lspcon_active && crtc_state->ycbcr420)
>> +		temp |= TRANS_MSA_SAMPLING_444 | TRANS_MSA_CLRSP_YCBCR;
>>   	I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
>>   }
>>   
>> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
>> index 737de25..787119b 100644
>> --- a/drivers/gpu/drm/i915/intel_display.c
>> +++ b/drivers/gpu/drm/i915/intel_display.c
>> @@ -4638,7 +4638,8 @@ skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
>>   	 */
>>   	need_scaling = src_w != dst_w || src_h != dst_h;
>>   
>> -	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX)
>> +	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX &&
>> +		!crtc_state->lspcon_active)
>>   		need_scaling = true;
>>   
>>   	/*
>> @@ -8133,9 +8134,15 @@ static void haswell_set_pipemisc(struct drm_crtc *crtc)
>>   			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
>>   
>>   		if (config->ycbcr420) {
>> -			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV |
>> -				PIPEMISC_YUV420_ENABLE |
>> -				PIPEMISC_YUV420_MODE_FULL_BLEND;
>> +			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV;
>> +			/*
>> +			 * LSPCON doesn't need scaling/blending to be done in
>> +			 * pipe. It just needs YCBCR444 input and proper AVI
>> +			 * infoframes for 4:2:0 output enabling.
>> +			 */
>> +			if (!config->lspcon_active)
>> +				val |= PIPEMISC_YUV420_ENABLE |
>> +				       PIPEMISC_YUV420_MODE_FULL_BLEND;
>>   		}
>>   
>>   		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
>> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
>> index fa9e5e6..1d4b669 100644
>> --- a/drivers/gpu/drm/i915/intel_dp.c
>> +++ b/drivers/gpu/drm/i915/intel_dp.c
>> @@ -1657,8 +1657,13 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>>   						    intel_dp->max_link_rate);
>>   
>>   	/* LSPCON needs special handling to drive YCBCR420 outputs */
>> -	if (lspcon->active)
>> +	if (lspcon->active) {
>> +		struct drm_connector *connector = &intel_connector->base;
>> +
>>   		pipe_config->lspcon_active = true;
>> +		pipe_config->ycbcr420 = lspcon_ycbcr420_config(connector,
>> +							       pipe_config);
>> +	}
>>   
>>   	/* No common link rates between source and sink */
>>   	WARN_ON(common_len <= 0);
>> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
>> index a468dd6..f271967 100644
>> --- a/drivers/gpu/drm/i915/intel_drv.h
>> +++ b/drivers/gpu/drm/i915/intel_drv.h
>> @@ -2047,6 +2047,8 @@ void lspcon_set_infoframes(struct drm_encoder *encoder,
>>   			   const struct drm_connector_state *conn_state);
>>   bool lspcon_infoframe_enabled(struct drm_encoder *encoder,
>>   			      const struct intel_crtc_state *pipe_config);
>> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
>> +			     struct intel_crtc_state *config);
>>   
>>   /* intel_pipe_crc.c */
>>   int intel_pipe_crc_create(struct drm_minor *minor);
>> diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
>> index 77f0687..ca77f50 100644
>> --- a/drivers/gpu/drm/i915/intel_lspcon.c
>> +++ b/drivers/gpu/drm/i915/intel_lspcon.c
>> @@ -180,6 +180,26 @@ static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
>>   	return true;
>>   }
>>   
>> +bool lspcon_ycbcr420_config(struct drm_connector *connector,
>> +			     struct intel_crtc_state *config)
>> +{
>> +	struct drm_display_info *info = &connector->display_info;
>> +	struct drm_display_mode *mode = &config->base.adjusted_mode;
>> +
>> +	if (drm_mode_is_420_only(info, mode)) {
>> +
>> +		if (!connector->ycbcr_420_allowed) {
>> +			DRM_ERROR("Platform doesn't support YCBCR420 output\n");
>> +			return false;
>> +		}
> Seems to be always true if lspcon->active is true?
Actually you are correct, if HAS_LSPCON && lspcon->active, ycbcr_420 
will be always allowed. But as we added this flag specifically to 
control 4:2:0 support from connector, for HDMI 2.0 native controllers, I 
though it would be more readable to use this flag. Do you think so ?
>> +		config->port_clock /= 2;
>> +		return true;
>> +	}
>> +
>> +	return false;
>> +}
>> +
>>   static bool lspcon_probe(struct intel_lspcon *lspcon)
>>   {
>>   	int retry;
>> @@ -516,6 +536,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>>   	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
>>   	struct drm_device *dev = intel_dig_port->base.base.dev;
>>   	struct drm_i915_private *dev_priv = to_i915(dev);
>> +	struct drm_connector *connector = &dp->attached_connector->base;
>>   
>>   	if (!HAS_LSPCON(dev_priv)) {
>>   		DRM_ERROR("LSPCON is not supported on this platform\n");
>> @@ -540,6 +561,7 @@ bool lspcon_init(struct intel_digital_port *intel_dig_port)
>>   		return false;
>>   	}
>>   
>> +	connector->ycbcr_420_allowed = true;
> Is this flag different from lspcon->active?
Yes, when we designed HDMI 2.0 native controller from GLK and plus 
platforms, we added this connector flag, so that, for the platforms 
which do not support 4:2:0 outputs, 4:2:0 only modes will be rejected 
from EDID's list of modes. This is the place where connector allows the 
4:2:0 capability, based on the platform, whereas is_lspcon is fro the 
encoder and state.
>>   	lspcon->active = true;
>>   	DRM_DEBUG_KMS("Success: LSPCON init\n");
>>   	return true;
> Comments from Ville still apply too. The pipe is set to ycbcr mode, so it makes more sense to have a ycbcr444 flag or something, and a separate flag to downconvert lspcon.
>
> It would be really nice if we could set the ycbcr444 flag in hw readout, and intel_pipe_config_compare. This way we know the sw mode matches the hw mode. :)
We will eventually need the right colorspace information while 
programming the AVI IF.
Actually we are trying to accommodate LSPCON into HDMI 2.0 framework as 
such. If you analyze the native 4:2:0 framework, there also we need 
scaling down, for which we use PIPEMISC register. So the requirement for 
GLK would be:
- one flag like YCBCR444 for pipe config (say state->444) to set CSC
- one flag in state to let modeset know that we have to program PIPEMISC 
and reserve a pipe_scaler (say state->420)
- one flag to set avi_if colorspace to ycbcr420 (again state->420, here 
we can't use 444, as we need accurate colorspace)

Now, in case of LSPCON,
- I still need state->444 to set CSC
- In modeset, I don't need to program PIPEMISC and scalar, as scaling 
happens in LSPCON internally so I need to know if this is LSPCON (hence 
state->lspcon)
- One flag to set appropriate avi_infoframes (so state->420)

So I realized even if I use state->444, I still need a state->420 flags 
to set correct colorspace in the avi infoframes, so there is no benefit 
of making this change.

Please let me know your opinion.

- Shashank
> ~Maarten
>
diff mbox

Patch

diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f0f8f60..ea6ef5e 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -8495,6 +8495,8 @@  enum skl_power_gate {
 #define TRANS_MSA_MISC(tran) _MMIO_TRANS2(tran, _TRANSA_MSA_MISC)
 
 #define  TRANS_MSA_SYNC_CLK		(1<<0)
+#define  TRANS_MSA_SAMPLING_444        (2<<1)
+#define  TRANS_MSA_CLRSP_YCBCR		(2<<3)
 #define  TRANS_MSA_6_BPC		(0<<5)
 #define  TRANS_MSA_8_BPC		(1<<5)
 #define  TRANS_MSA_10_BPC		(2<<5)
diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
index 9e2ab02..3fd839d 100644
--- a/drivers/gpu/drm/i915/intel_ddi.c
+++ b/drivers/gpu/drm/i915/intel_ddi.c
@@ -1499,6 +1499,14 @@  void intel_ddi_set_pipe_settings(const struct intel_crtc_state *crtc_state)
 		break;
 	}
 
+	/*
+	 * To get YCBCR 420 output from LSPCON, we should send YCBCR 444
+	 * signals. And as per DP 1.2 spec section 2.3.4.3 while sending
+	 * YCBCR 444 signals we should program MSA MISC1/0 fields with
+	 * colorspace information.
+	 */
+	if (crtc_state->lspcon_active && crtc_state->ycbcr420)
+		temp |= TRANS_MSA_SAMPLING_444 | TRANS_MSA_CLRSP_YCBCR;
 	I915_WRITE(TRANS_MSA_MISC(cpu_transcoder), temp);
 }
 
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 737de25..787119b 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -4638,7 +4638,8 @@  skl_update_scaler(struct intel_crtc_state *crtc_state, bool force_detach,
 	 */
 	need_scaling = src_w != dst_w || src_h != dst_h;
 
-	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX)
+	if (crtc_state->ycbcr420 && scaler_user == SKL_CRTC_INDEX &&
+		!crtc_state->lspcon_active)
 		need_scaling = true;
 
 	/*
@@ -8133,9 +8134,15 @@  static void haswell_set_pipemisc(struct drm_crtc *crtc)
 			val |= PIPEMISC_DITHER_ENABLE | PIPEMISC_DITHER_TYPE_SP;
 
 		if (config->ycbcr420) {
-			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV |
-				PIPEMISC_YUV420_ENABLE |
-				PIPEMISC_YUV420_MODE_FULL_BLEND;
+			val |= PIPEMISC_OUTPUT_COLORSPACE_YUV;
+			/*
+			 * LSPCON doesn't need scaling/blending to be done in
+			 * pipe. It just needs YCBCR444 input and proper AVI
+			 * infoframes for 4:2:0 output enabling.
+			 */
+			if (!config->lspcon_active)
+				val |= PIPEMISC_YUV420_ENABLE |
+				       PIPEMISC_YUV420_MODE_FULL_BLEND;
 		}
 
 		I915_WRITE(PIPEMISC(intel_crtc->pipe), val);
diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
index fa9e5e6..1d4b669 100644
--- a/drivers/gpu/drm/i915/intel_dp.c
+++ b/drivers/gpu/drm/i915/intel_dp.c
@@ -1657,8 +1657,13 @@  intel_dp_compute_config(struct intel_encoder *encoder,
 						    intel_dp->max_link_rate);
 
 	/* LSPCON needs special handling to drive YCBCR420 outputs */
-	if (lspcon->active)
+	if (lspcon->active) {
+		struct drm_connector *connector = &intel_connector->base;
+
 		pipe_config->lspcon_active = true;
+		pipe_config->ycbcr420 = lspcon_ycbcr420_config(connector,
+							       pipe_config);
+	}
 
 	/* No common link rates between source and sink */
 	WARN_ON(common_len <= 0);
diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
index a468dd6..f271967 100644
--- a/drivers/gpu/drm/i915/intel_drv.h
+++ b/drivers/gpu/drm/i915/intel_drv.h
@@ -2047,6 +2047,8 @@  void lspcon_set_infoframes(struct drm_encoder *encoder,
 			   const struct drm_connector_state *conn_state);
 bool lspcon_infoframe_enabled(struct drm_encoder *encoder,
 			      const struct intel_crtc_state *pipe_config);
+bool lspcon_ycbcr420_config(struct drm_connector *connector,
+			     struct intel_crtc_state *config);
 
 /* intel_pipe_crc.c */
 int intel_pipe_crc_create(struct drm_minor *minor);
diff --git a/drivers/gpu/drm/i915/intel_lspcon.c b/drivers/gpu/drm/i915/intel_lspcon.c
index 77f0687..ca77f50 100644
--- a/drivers/gpu/drm/i915/intel_lspcon.c
+++ b/drivers/gpu/drm/i915/intel_lspcon.c
@@ -180,6 +180,26 @@  static bool lspcon_wake_native_aux_ch(struct intel_lspcon *lspcon)
 	return true;
 }
 
+bool lspcon_ycbcr420_config(struct drm_connector *connector,
+			     struct intel_crtc_state *config)
+{
+	struct drm_display_info *info = &connector->display_info;
+	struct drm_display_mode *mode = &config->base.adjusted_mode;
+
+	if (drm_mode_is_420_only(info, mode)) {
+
+		if (!connector->ycbcr_420_allowed) {
+			DRM_ERROR("Platform doesn't support YCBCR420 output\n");
+			return false;
+		}
+
+		config->port_clock /= 2;
+		return true;
+	}
+
+	return false;
+}
+
 static bool lspcon_probe(struct intel_lspcon *lspcon)
 {
 	int retry;
@@ -516,6 +536,7 @@  bool lspcon_init(struct intel_digital_port *intel_dig_port)
 	struct intel_lspcon *lspcon = &intel_dig_port->lspcon;
 	struct drm_device *dev = intel_dig_port->base.base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_connector *connector = &dp->attached_connector->base;
 
 	if (!HAS_LSPCON(dev_priv)) {
 		DRM_ERROR("LSPCON is not supported on this platform\n");
@@ -540,6 +561,7 @@  bool lspcon_init(struct intel_digital_port *intel_dig_port)
 		return false;
 	}
 
+	connector->ycbcr_420_allowed = true;
 	lspcon->active = true;
 	DRM_DEBUG_KMS("Success: LSPCON init\n");
 	return true;