[Intel-gfx] [PATCH 1/2] drm/i915: Set M2_N2 registers during mode set

[Jesse Barnes]

On Mon,  7 Jul 2014 14:59:45 +0530
Vandana Kannan <vandana.kannan at intel.com> wrote:

> For Gen < 8, set M2_N2 registers on every mode set. This is required to make
> sure M2_N2 registers are set during boot, resume from sleep for cross-
> checking the state. The register is set only if DRRS is supported.
> 
> v2: Patch rebased
> 
> v3: Daniel's review comments
> 	- Removed HAS_DRRS(dev) and added bool has_drrs to pipe_config to
> 	track drrs support
> 
> Signed-off-by: Vandana Kannan <vandana.kannan at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> ---
>  drivers/gpu/drm/i915/intel_display.c | 36 ++++++++++++++++++++++++++++++++----
>  drivers/gpu/drm/i915/intel_dp.c      | 16 ++--------------
>  drivers/gpu/drm/i915/intel_drv.h     |  2 ++
>  3 files changed, 36 insertions(+), 18 deletions(-)
> 
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index a72b55f..22bdea5f 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -4020,8 +4020,12 @@ static void ironlake_crtc_enable(struct drm_crtc *crtc)
>  	if (intel_crtc->config.has_pch_encoder)
>  		intel_prepare_shared_dpll(intel_crtc);
>  
> -	if (intel_crtc->config.has_dp_encoder)
> +	if (intel_crtc->config.has_dp_encoder) {
>  		intel_dp_set_m_n(intel_crtc);
> +		if (INTEL_INFO(dev)->gen < 8 && intel_crtc->config.has_drrs)
> +			intel_dp_set_m2_n2(intel_crtc,
> +				&intel_crtc->config.dp_m2_n2);
> +	}
>  
>  	intel_set_pipe_timings(intel_crtc);
>  
> @@ -4130,8 +4134,12 @@ static void haswell_crtc_enable(struct drm_crtc *crtc)
>  	if (intel_crtc->active)
>  		return;
>  
> -	if (intel_crtc->config.has_dp_encoder)
> +	if (intel_crtc->config.has_dp_encoder) {
>  		intel_dp_set_m_n(intel_crtc);
> +		if (INTEL_INFO(dev)->gen < 8 && intel_crtc->config.has_drrs)
> +			intel_dp_set_m2_n2(intel_crtc,
> +					&intel_crtc->config.dp_m2_n2);
> +	}
>  
>  	intel_set_pipe_timings(intel_crtc);
>  
> @@ -4648,8 +4656,12 @@ static void valleyview_crtc_enable(struct drm_crtc *crtc)
>  	/* Set up the display plane register */
>  	dspcntr = DISPPLANE_GAMMA_ENABLE;
>  
> -	if (intel_crtc->config.has_dp_encoder)
> +	if (intel_crtc->config.has_dp_encoder) {
>  		intel_dp_set_m_n(intel_crtc);
> +		if (INTEL_INFO(dev)->gen < 8 && intel_crtc->config.has_drrs)
> +			intel_dp_set_m2_n2(intel_crtc,
> +					&intel_crtc->config.dp_m2_n2);
> +	}
>  
>  	intel_set_pipe_timings(intel_crtc);
>  
> @@ -4738,8 +4750,12 @@ static void i9xx_crtc_enable(struct drm_crtc *crtc)
>  	else
>  		dspcntr |= DISPPLANE_SEL_PIPE_B;
>  
> -	if (intel_crtc->config.has_dp_encoder)
> +	if (intel_crtc->config.has_dp_encoder) {
>  		intel_dp_set_m_n(intel_crtc);
> +		if (INTEL_INFO(dev)->gen < 8 && intel_crtc->config.has_drrs)
> +			intel_dp_set_m2_n2(intel_crtc,
> +					&intel_crtc->config.dp_m2_n2);
> +	}
>  
>  	intel_set_pipe_timings(intel_crtc);
>  
> @@ -5530,6 +5546,18 @@ static void intel_dp_set_m_n(struct intel_crtc *crtc)
>  		intel_cpu_transcoder_set_m_n(crtc, &crtc->config.dp_m_n);
>  }
>  
> +void intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n)
> +{
> +	struct drm_device *dev = crtc->base.dev;
> +	struct drm_i915_private *dev_priv = dev->dev_private;
> +	enum transcoder transcoder = crtc->config.cpu_transcoder;
> +
> +	I915_WRITE(PIPE_DATA_M2(transcoder), TU_SIZE(m_n->tu) | m_n->gmch_m);
> +	I915_WRITE(PIPE_DATA_N2(transcoder), m_n->gmch_n);
> +	I915_WRITE(PIPE_LINK_M2(transcoder), m_n->link_m);
> +	I915_WRITE(PIPE_LINK_N2(transcoder), m_n->link_n);
> +}
> +
>  static void vlv_update_pll(struct intel_crtc *crtc)
>  {
>  	u32 dpll, dpll_md;
> diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c
> index b5ec489..1c3960b 100644
> --- a/drivers/gpu/drm/i915/intel_dp.c
> +++ b/drivers/gpu/drm/i915/intel_dp.c
> @@ -780,20 +780,6 @@ intel_dp_set_clock(struct intel_encoder *encoder,
>  	}
>  }
>  
> -static void
> -intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n)
> -{
> -	struct drm_device *dev = crtc->base.dev;
> -	struct drm_i915_private *dev_priv = dev->dev_private;
> -	enum transcoder transcoder = crtc->config.cpu_transcoder;
> -
> -	I915_WRITE(PIPE_DATA_M2(transcoder),
> -		TU_SIZE(m_n->tu) | m_n->gmch_m);
> -	I915_WRITE(PIPE_DATA_N2(transcoder), m_n->gmch_n);
> -	I915_WRITE(PIPE_LINK_M2(transcoder), m_n->link_m);
> -	I915_WRITE(PIPE_LINK_N2(transcoder), m_n->link_n);
> -}
> -
>  bool
>  intel_dp_compute_config(struct intel_encoder *encoder,
>  			struct intel_crtc_config *pipe_config)
> @@ -819,6 +805,7 @@ intel_dp_compute_config(struct intel_encoder *encoder,
>  		pipe_config->has_pch_encoder = true;
>  
>  	pipe_config->has_dp_encoder = true;
> +	pipe_config->has_drrs = false;
>  	pipe_config->has_audio = intel_dp->has_audio;
>  
>  	if (is_edp(intel_dp) && intel_connector->panel.fixed_mode) {
> @@ -922,6 +909,7 @@ found:
>  
>  	if (intel_connector->panel.downclock_mode != NULL &&
>  		intel_dp->drrs_state.type == SEAMLESS_DRRS_SUPPORT) {
> +			pipe_config->has_drrs = true;
>  			intel_link_compute_m_n(bpp, lane_count,
>  				intel_connector->panel.downclock_mode->clock,
>  				pipe_config->port_clock,
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 5f7c7bd..d35b1ed 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -315,6 +315,7 @@ struct intel_crtc_config {
>  
>  	/* m2_n2 for eDP downclock */
>  	struct intel_link_m_n dp_m2_n2;
> +	bool has_drrs;
>  
>  	/*
>  	 * Frequence the dpll for the port should run at. Differs from the
> @@ -836,6 +837,7 @@ void intel_mode_from_pipe_config(struct drm_display_mode *mode,
>  				 struct intel_crtc_config *pipe_config);
>  int intel_format_to_fourcc(int format);
>  void intel_crtc_wait_for_pending_flips(struct drm_crtc *crtc);
> +void intel_dp_set_m2_n2(struct intel_crtc *crtc, struct intel_link_m_n *m_n);
>  
>  
>  /* intel_dp.c */

One potential cleanup would be to move the setting of the m2/n2 pair
into the set_m_n function itself.  That would save us from sprinkling
checks all over.

Also, we could make the check depend just on has_drrs, I think the gen8
check is redundant?

But those can go on top I think, otherwise looks ok.

-- 
Jesse Barnes, Intel Open Source Technology Center