[Intel-gfx] [PATCH v6 18/28] drm/i915/dp: Enable/Disable DSC in DP Sink

[Manasi Navare]

On Thu, Oct 25, 2018 at 05:03:06PM +0300, Ville Syrjälä wrote:
> On Wed, Oct 24, 2018 at 03:28:30PM -0700, Manasi Navare wrote:
> > From: Gaurav K Singh <gaurav.k.singh at intel.com>
> > 
> > This patch enables decompression support in sink device
> > before link training and disables the same during the
> > DDI disabling.
> > 
> > v2:(From Manasi)
> > * Change the enable/disable function to take crtc_state
> > instead of intel_dp as an argument (Manasi)
> > * Use the compression_enable flag as part of crtc_state (Manasi)
> > 
> > Cc: Jani Nikula <jani.nikula at linux.intel.com>
> > Cc: Ville Syrjala <ville.syrjala at linux.intel.com>
> > Cc: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > Cc: Gaurav K Singh <gaurav.k.singh at intel.com>
> > Signed-off-by: Gaurav K Singh <gaurav.k.singh at intel.com>
> > Signed-off-by: Manasi Navare <manasi.d.navare at intel.com>
> > Reviewed-by: Anusha Srivatsa <anusha.srivatsa at intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c |  5 +++++
> >  drivers/gpu/drm/i915/intel_dp.c  | 15 +++++++++++++++
> >  drivers/gpu/drm/i915/intel_drv.h |  3 +++
> >  3 files changed, 23 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index e40a8c97d34b..1de0a3917d7f 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -2930,6 +2930,8 @@ static void intel_ddi_pre_enable_dp(struct intel_encoder *encoder,
> >  	intel_ddi_init_dp_buf_reg(encoder);
> >  	if (!is_mst)
> >  		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
> > +	intel_dp_sink_set_decompression_state(intel_dp, crtc_state,
> > +					      DP_DECOMPRESSION_EN);
> >  	intel_dp_start_link_train(intel_dp);
> >  	if (port != PORT_A || INTEL_GEN(dev_priv) >= 9)
> >  		intel_dp_stop_link_train(intel_dp);
> > @@ -3272,6 +3274,9 @@ static void intel_disable_ddi_dp(struct intel_encoder *encoder,
> >  	intel_edp_drrs_disable(intel_dp, old_crtc_state);
> >  	intel_psr_disable(intel_dp, old_crtc_state);
> >  	intel_edp_backlight_off(old_conn_state);
> > +	/* Disable the decompression in DP Sink */
> > +	intel_dp_sink_set_decompression_state(intel_dp, old_crtc_state,
> > +					      ~DP_DECOMPRESSION_EN);
> 
> That looks suspicious.
> 
> I can't figure out what value you're actually passing here since I
> can't find the definiiton of DP_DECOMPRESSION_EN anywhere.

This is defined in /include/drm/drm_dp_helper.h

Manasi

> 
> >  }
> >  
> >  static void intel_disable_ddi_hdmi(struct intel_encoder *encoder,
> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> > index 35162c3bc811..72e6605f0ed7 100644
> > --- a/drivers/gpu/drm/i915/intel_dp.c
> > +++ b/drivers/gpu/drm/i915/intel_dp.c
> > @@ -3005,6 +3005,21 @@ static bool downstream_hpd_needs_d0(struct intel_dp *intel_dp)
> >  		intel_dp->downstream_ports[0] & DP_DS_PORT_HPD;
> >  }
> >  
> > +void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
> > +					   const struct intel_crtc_state *crtc_state,
> > +					   int state)
> > +{
> > +	int ret;
> > +
> > +	if (!crtc_state->dsc_params.compression_enable)
> > +		return;
> > +
> > +	ret = drm_dp_dpcd_writeb(&intel_dp->aux, DP_DSC_ENABLE, state);
> > +	if (ret < 0)
> > +		DRM_DEBUG_KMS("Failed to %s sink decompression state\n",
> > +			      state == DP_DECOMPRESSION_EN ? "enable" : "disable");
> > +}
> > +
> >  /* If the sink supports it, try to set the power state appropriately */
> >  void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode)
> >  {
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index c4be4ba7adac..4f5d17bcd54e 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -1786,6 +1786,9 @@ void intel_dp_stop_link_train(struct intel_dp *intel_dp);
> >  int intel_dp_retrain_link(struct intel_encoder *encoder,
> >  			  struct drm_modeset_acquire_ctx *ctx);
> >  void intel_dp_sink_dpms(struct intel_dp *intel_dp, int mode);
> > +void intel_dp_sink_set_decompression_state(struct intel_dp *intel_dp,
> > +					   const struct intel_crtc_state *crtc_state,
> > +					   int state);
> >  void intel_dp_encoder_reset(struct drm_encoder *encoder);
> >  void intel_dp_encoder_suspend(struct intel_encoder *intel_encoder);
> >  void intel_dp_encoder_destroy(struct drm_encoder *encoder);
> > -- 
> > 2.18.0
> 
> -- 
> Ville Syrjälä
> Intel