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

ville.syrjala at linux.intel.com ville.syrjala at linux.intel.com
Wed Dec 21 09:31:05 UTC 2016


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.

Cc: Paulo Zanoni <paulo.r.zanoni at intel.com>
Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
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;
 
 	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..708cf1d419d4 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_force_disable != 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;
-- 
2.10.2



More information about the Intel-gfx mailing list