Re: [PATCH] drm/i915: Try to fix MST for SKL

["Ville Syrjälä" <ville.syrjala@linux.intel.com>]

On Tue, Nov 10, 2015 at 12:15:40PM -0800, Jesse Barnes wrote:
> On 08/17/2015 08:46 AM, ville.syrjala@linux.intel.com wrote:
> > From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > 
> > Set up the DDI->PLL mapping on SKL also for MST links. Might help make
> > MST operational on SKL.
> > 
> > Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> > Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_ddi.c    | 49 ++++++++++++++++++++++---------------
> >  drivers/gpu/drm/i915/intel_dp_mst.c |  8 +-----
> >  drivers/gpu/drm/i915/intel_drv.h    |  2 ++
> >  3 files changed, 32 insertions(+), 27 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/i915/intel_ddi.c b/drivers/gpu/drm/i915/intel_ddi.c
> > index 5dff8b7..10a5a98 100644
> > --- a/drivers/gpu/drm/i915/intel_ddi.c
> > +++ b/drivers/gpu/drm/i915/intel_ddi.c
> > @@ -2258,30 +2258,21 @@ uint32_t ddi_signal_levels(struct intel_dp *intel_dp)
> >  	return DDI_BUF_TRANS_SELECT(level);
> >  }
> >  
> > -static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
> > +void intel_ddi_clk_select(struct intel_encoder *encoder,
> > +			  const struct intel_crtc_state *pipe_config)
> >  {
> > -	struct drm_encoder *encoder = &intel_encoder->base;
> > -	struct drm_device *dev = encoder->dev;
> > -	struct drm_i915_private *dev_priv = dev->dev_private;
> > -	struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
> > -	enum port port = intel_ddi_get_encoder_port(intel_encoder);
> > -	int type = intel_encoder->type;
> > -	int hdmi_level;
> > -
> > -	if (type == INTEL_OUTPUT_EDP) {
> > -		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> > -		intel_edp_panel_on(intel_dp);
> > -	}
> > +	struct drm_i915_private *dev_priv = to_i915(encoder->base.dev);
> > +	enum port port = intel_ddi_get_encoder_port(encoder);
> >  
> > -	if (IS_SKYLAKE(dev)) {
> > -		uint32_t dpll = crtc->config->ddi_pll_sel;
> > +	if (IS_SKYLAKE(dev_priv)) {
> > +		uint32_t dpll = pipe_config->ddi_pll_sel;
> >  		uint32_t val;
> >  
> >  		/*
> >  		 * DPLL0 is used for eDP and is the only "private" DPLL (as
> >  		 * opposed to shared) on SKL
> >  		 */
> > -		if (type == INTEL_OUTPUT_EDP) {
> > +		if (encoder->type == INTEL_OUTPUT_EDP) {
> >  			WARN_ON(dpll != SKL_DPLL0);
> >  
> >  			val = I915_READ(DPLL_CTRL1);
> > @@ -2289,7 +2280,7 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
> >  			val &= ~(DPLL_CTRL1_HDMI_MODE(dpll) |
> >  				 DPLL_CTRL1_SSC(dpll) |
> >  				 DPLL_CTRL1_LINK_RATE_MASK(dpll));
> > -			val |= crtc->config->dpll_hw_state.ctrl1 << (dpll * 6);
> > +			val |= pipe_config->dpll_hw_state.ctrl1 << (dpll * 6);
> >  
> >  			I915_WRITE(DPLL_CTRL1, val);
> >  			POSTING_READ(DPLL_CTRL1);
> > @@ -2305,11 +2296,29 @@ static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
> >  
> >  		I915_WRITE(DPLL_CTRL2, val);
> >  
> > -	} else if (INTEL_INFO(dev)->gen < 9) {
> > -		WARN_ON(crtc->config->ddi_pll_sel == PORT_CLK_SEL_NONE);
> > -		I915_WRITE(PORT_CLK_SEL(port), crtc->config->ddi_pll_sel);
> > +	} else if (INTEL_INFO(dev_priv)->gen < 9) {
> > +		WARN_ON(pipe_config->ddi_pll_sel == PORT_CLK_SEL_NONE);
> > +		I915_WRITE(PORT_CLK_SEL(port), pipe_config->ddi_pll_sel);
> > +	}
> > +}
> > +
> > +static void intel_ddi_pre_enable(struct intel_encoder *intel_encoder)
> > +{
> > +	struct drm_encoder *encoder = &intel_encoder->base;
> > +	struct drm_device *dev = encoder->dev;
> > +	struct drm_i915_private *dev_priv = dev->dev_private;
> > +	struct intel_crtc *crtc = to_intel_crtc(encoder->crtc);
> > +	enum port port = intel_ddi_get_encoder_port(intel_encoder);
> > +	int type = intel_encoder->type;
> > +	int hdmi_level;
> > +
> > +	if (type == INTEL_OUTPUT_EDP) {
> > +		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> > +		intel_edp_panel_on(intel_dp);
> >  	}
> >  
> > +	intel_ddi_clk_select(intel_encoder, crtc->config);
> > +
> >  	if (type == INTEL_OUTPUT_DISPLAYPORT || type == INTEL_OUTPUT_EDP) {
> >  		struct intel_dp *intel_dp = enc_to_intel_dp(encoder);
> >  
> > diff --git a/drivers/gpu/drm/i915/intel_dp_mst.c b/drivers/gpu/drm/i915/intel_dp_mst.c
> > index ebf2054..fd25aeb7 100644
> > --- a/drivers/gpu/drm/i915/intel_dp_mst.c
> > +++ b/drivers/gpu/drm/i915/intel_dp_mst.c
> > @@ -163,20 +163,14 @@ static void intel_mst_pre_enable_dp(struct intel_encoder *encoder)
> >  	intel_mst->port = found->port;
> >  
> >  	if (intel_dp->active_mst_links == 0) {
> > -		enum port port = intel_ddi_get_encoder_port(encoder);
> > +		intel_ddi_clk_select(encoder, intel_crtc->config);
> >  
> >  		intel_dp_set_link_params(intel_dp, intel_crtc->config);
> >  
> > -		/* FIXME: add support for SKL */
> > -		if (INTEL_INFO(dev)->gen < 9)
> > -			I915_WRITE(PORT_CLK_SEL(port),
> > -				   intel_crtc->config->ddi_pll_sel);
> > -
> >  		intel_ddi_init_dp_buf_reg(&intel_dig_port->base);
> >  
> >  		intel_dp_sink_dpms(intel_dp, DRM_MODE_DPMS_ON);
> >  
> > -
> >  		intel_dp_start_link_train(intel_dp);
> >  		intel_dp_complete_link_train(intel_dp);
> >  		intel_dp_stop_link_train(intel_dp);
> > diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> > index 71a2e18..a97908a 100644
> > --- a/drivers/gpu/drm/i915/intel_drv.h
> > +++ b/drivers/gpu/drm/i915/intel_drv.h
> > @@ -938,6 +938,8 @@ void intel_crt_init(struct drm_device *dev);
> >  
> >  
> >  /* intel_ddi.c */
> > +void intel_ddi_clk_select(struct intel_encoder *encoder,
> > +			  const struct intel_crtc_state *pipe_config);
> >  void intel_prepare_ddi(struct drm_device *dev);
> >  void hsw_fdi_link_train(struct drm_crtc *crtc);
> >  void intel_ddi_init(struct drm_device *dev, enum port port);
> > 
> 
> Looks like an improvement over current code and fixes the hard hang in
> https://bugs.freedesktop.org/show_bug.cgi?id=91791, so I think we should
> push it.
> 
> Sounds like we need more than just this to fix MST on SKL though.
> 
> Reviewed-by: Jesse Barnes <jbarnes@virtuousgeek.org>

Patch merged to dinq with an improved subject:
"drm/i915: Setup DDI clk for MST on SKL"

... which apparently made the patchwork link invalid somehow:
"remote: Updating patchwork state for http://patchwork.freedesktop.org/project/intel-gfx/list/
 remote: E: failed to find patch for rev e404ba8d06ff2a1bdb916a9e5d2c09cacd7e5ca3
 remote: I: 0 patch(es) updated to state Accepted."

Anyway, thanks for the r-b.

-- 
Ville Syrjälä
Intel OTC
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