[Intel-gfx] [PATCH v2] drm/i915: Beef up the IPS vs. CRC workaround

Maarten Lankhorst maarten.lankhorst at linux.intel.com
Thu Aug 17 08:00:52 UTC 2017


Op 16-08-17 om 16:39 schreef ville.syrjala at linux.intel.com:
> From: Ville Syrjälä <ville.syrjala at linux.intel.com>
>
> Oneshot disabling of IPS when CRC capturing is started is insufficient.
> IPS may get re-enabled by any plane update, and hence tests that keep
> CRC capturing on across plane updates will start to see inconsistent
> results as soon as IPS kicks back in. Add a new knob into the crtc state
> to make sure IPS stays disabled as long as CRC capturing is enabled.
>
> Forcing a modeset is the easiest way to handle this since that's already
> how we do the panel fitter workaround. It's a little heavy handed just
> for IPS, but seeing as we might already do the panel fitter workaround
> I think it's better to follow that. We migth want to optimize both cases
> later if someone gets too upset by the extra delay from the modeset.
>
> v2: Check the right thing when deciding whether to force a modeset
>
> Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
> Cc: Marta Lofstedt <marta.lofstedt at intel.com>
> Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101664
> Reviewed-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
> Signed-off-by: Ville Syrjälä <ville.syrjala at linux.intel.com>
> ---
>  drivers/gpu/drm/i915/intel_display.c  |  5 +++-
>  drivers/gpu/drm/i915/intel_drv.h      |  1 +
>  drivers/gpu/drm/i915/intel_pipe_crc.c | 43 +++++++++++++++++++----------------
>  3 files changed, 28 insertions(+), 21 deletions(-)
>
> diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
> index ef5dde5ab1cf..1ce479614f52 100644
> --- a/drivers/gpu/drm/i915/intel_display.c
> +++ b/drivers/gpu/drm/i915/intel_display.c
> @@ -7189,6 +7189,7 @@ static void hsw_compute_ips_config(struct intel_crtc *crtc,
>  	struct drm_i915_private *dev_priv = to_i915(dev);
>  
>  	pipe_config->ips_enabled = i915.enable_ips &&
> +		!pipe_config->ips_force_disable &&
>  		hsw_crtc_supports_ips(crtc) &&
>  		pipe_config_supports_ips(dev_priv, pipe_config);
>  }
> @@ -12958,7 +12959,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
>  	struct intel_crtc_scaler_state scaler_state;
>  	struct intel_dpll_hw_state dpll_hw_state;
>  	struct intel_shared_dpll *shared_dpll;
> -	bool force_thru;
> +	bool force_thru, ips_force_disable;
>  
>  	/* FIXME: before the switch to atomic started, a new pipe_config was
>  	 * kzalloc'd. Code that depends on any field being zero should be
> @@ -12970,6 +12971,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
>  	shared_dpll = crtc_state->shared_dpll;
>  	dpll_hw_state = crtc_state->dpll_hw_state;
>  	force_thru = crtc_state->pch_pfit.force_thru;
> +	ips_force_disable = crtc_state->ips_force_disable;
>  
>  	memset(crtc_state, 0, sizeof *crtc_state);
>  
> @@ -12978,6 +12980,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
>  	crtc_state->shared_dpll = shared_dpll;
>  	crtc_state->dpll_hw_state = dpll_hw_state;
>  	crtc_state->pch_pfit.force_thru = force_thru;
> +	crtc_state->ips_force_disable = ips_force_disable;
>  }
>  
>  static int
> diff --git a/drivers/gpu/drm/i915/intel_drv.h b/drivers/gpu/drm/i915/intel_drv.h
> index 025e4c8b3e63..cadba9b92cc9 100644
> --- a/drivers/gpu/drm/i915/intel_drv.h
> +++ b/drivers/gpu/drm/i915/intel_drv.h
> @@ -651,6 +651,7 @@ struct intel_crtc_state {
>  	struct intel_link_m_n fdi_m_n;
>  
>  	bool ips_enabled;
> +	bool ips_force_disable;
Could we rename this to collecting_crc throughout the patch?

And as Marta noted, intel_crtc_set_crc_source also needs fixing. :)
>  
>  	bool enable_fbc;
>  
> diff --git a/drivers/gpu/drm/i915/intel_pipe_crc.c b/drivers/gpu/drm/i915/intel_pipe_crc.c
> index ef0c0e195164..74780b090d1e 100644
> --- a/drivers/gpu/drm/i915/intel_pipe_crc.c
> +++ b/drivers/gpu/drm/i915/intel_pipe_crc.c
> @@ -547,8 +547,8 @@ static int ilk_pipe_crc_ctl_reg(enum intel_pipe_crc_source *source,
>  	return 0;
>  }
>  
> -static void hsw_trans_edp_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
> -					bool enable)
> +static void hsw_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
> +			      bool enable)
>  {
>  	struct drm_device *dev = &dev_priv->drm;
>  	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, PIPE_A);
> @@ -570,11 +570,23 @@ static void hsw_trans_edp_pipe_A_crc_wa(struct drm_i915_private *dev_priv,
>  		goto out;
>  	}
>  
> -	pipe_config->pch_pfit.force_thru = enable;
> -	if (pipe_config->cpu_transcoder == TRANSCODER_EDP &&
> -	    pipe_config->pch_pfit.enabled != enable)
> +	/*
> +	 * When IPS gets enabled, the pipe CRC changes. Since IPS gets
> +	 * enabled and disabled dynamically based on package C states,
> +	 * user space can't make reliable use of the CRCs, so let's just
> +	 * completely disable it.
> +	 */
> +	pipe_config->ips_force_disable = enable;
> +	if (pipe_config->ips_enabled == enable)
>  		pipe_config->base.connectors_changed = true;
>  
> +	if (IS_HASWELL(dev_priv)) {
> +		pipe_config->pch_pfit.force_thru = enable;
> +		if (pipe_config->cpu_transcoder == TRANSCODER_EDP &&
> +		    pipe_config->pch_pfit.enabled != enable)
> +			pipe_config->base.connectors_changed = true;
> +	}
> +
>  	ret = drm_atomic_commit(state);
>  out:
>  	WARN(ret, "Toggling workaround to %i returns %i\n", enable, ret);
> @@ -598,8 +610,9 @@ static int ivb_pipe_crc_ctl_reg(struct drm_i915_private *dev_priv,
>  		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_SPRITE_IVB;
>  		break;
>  	case INTEL_PIPE_CRC_SOURCE_PF:
> -		if (IS_HASWELL(dev_priv) && pipe == PIPE_A)
> -			hsw_trans_edp_pipe_A_crc_wa(dev_priv, true);
> +		if ((IS_HASWELL(dev_priv) ||
> +		     IS_BROADWELL(dev_priv)) && pipe == PIPE_A)
> +			hsw_pipe_A_crc_wa(dev_priv, true);
>  
>  		*val = PIPE_CRC_ENABLE | PIPE_CRC_SOURCE_PF_IVB;
>  		break;
> @@ -618,7 +631,6 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
>  			       enum intel_pipe_crc_source source)
>  {
>  	struct intel_pipe_crc *pipe_crc = &dev_priv->pipe_crc[pipe];
> -	struct intel_crtc *crtc = intel_get_crtc_for_pipe(dev_priv, pipe);
>  	enum intel_display_power_domain power_domain;
>  	u32 val = 0; /* shut up gcc */
>  	int ret;
> @@ -665,14 +677,6 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
>  			goto out;
>  		}
>  
> -		/*
> -		 * When IPS gets enabled, the pipe CRC changes. Since IPS gets
> -		 * enabled and disabled dynamically based on package C states,
> -		 * user space can't make reliable use of the CRCs, so let's just
> -		 * completely disable it.
> -		 */
> -		hsw_disable_ips(crtc);
> -
>  		spin_lock_irq(&pipe_crc->lock);
>  		kfree(pipe_crc->entries);
>  		pipe_crc->entries = entries;
> @@ -713,10 +717,9 @@ static int pipe_crc_set_source(struct drm_i915_private *dev_priv,
>  			g4x_undo_pipe_scramble_reset(dev_priv, pipe);
>  		else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
>  			vlv_undo_pipe_scramble_reset(dev_priv, pipe);
> -		else if (IS_HASWELL(dev_priv) && pipe == PIPE_A)
> -			hsw_trans_edp_pipe_A_crc_wa(dev_priv, false);
> -
> -		hsw_enable_ips(crtc);
> +		else if ((IS_HASWELL(dev_priv) ||
> +			  IS_BROADWELL(dev_priv)) && pipe == PIPE_A)
> +			hsw_pipe_A_crc_wa(dev_priv, false);
>  	}
>  
>  	ret = 0;




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