drm/i915: Beef up the IPS vs. CRC workaround

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
v3: Rebase, check HAS_IPS before forcing a modeset,
    move ips_force_disable check into pipe_config_supports_ips()

Cc: Paulo Zanoni <paulo.r.zanoni@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Marta Lofstedt <marta.lofstedt@intel.com>
Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=101664
Reviewed-by: Paulo Zanoni <paulo.r.zanoni@intel.com>
Tested-by: Marta Lofsted <marta.lofstedt@intel.com> #v2
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170817145509.15549-1-ville.syrjala@linux.intel.com

drivers/gpu/drm/i915/intel_display.c

@@ -6263,6 +6263,9 @@ retry:
 static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
 				     struct intel_crtc_state *pipe_config)
 {
+	if (pipe_config->ips_force_disable)
+		return false;
+
 	if (pipe_config->pipe_bpp > 24)
 		return false;
 
@@ -10830,7 +10833,7 @@ clear_intel_crtc_state(struct intel_crtc_state *crtc_state)
 	struct intel_dpll_hw_state dpll_hw_state;
 	struct intel_shared_dpll *shared_dpll;
 	struct intel_crtc_wm_state wm_state;
-	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
@@ -10841,6 +10844,7 @@ 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;
 	if (IS_G4X(dev_priv) ||
 	    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
 		wm_state = crtc_state->wm;
@@ -10854,6 +10858,7 @@ 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;
 	if (IS_G4X(dev_priv) ||
 	    IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
 		crtc_state->wm = wm_state;

drivers/gpu/drm/i915/intel_drv.h

@@ -753,6 +753,7 @@ struct intel_crtc_state {
 	struct intel_link_m_n fdi_m_n;
 
 	bool ips_enabled;
+	bool ips_force_disable;
 
 	bool enable_fbc;
 

drivers/gpu/drm/i915/intel_pipe_crc.c

@@ -506,8 +506,8 @@ 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);
@@ -533,10 +533,24 @@ retry:
 		goto put_state;
 	}
 
-	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;
+	if (HAS_IPS(dev_priv)) {
+		/*
+		 * 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);
 
@@ -570,8 +584,9 @@ 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;
@@ -606,7 +621,6 @@ 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;
@@ -643,14 +657,6 @@ 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;
@@ -691,10 +697,9 @@ 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;
@@ -935,16 +940,6 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
 	if (ret != 0)
 		goto out;
 
-	if (source) {
-		/*
-		 * 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(intel_crtc);
-	}
-
 	I915_WRITE(PIPE_CRC_CTL(crtc->index), val);
 	POSTING_READ(PIPE_CRC_CTL(crtc->index));
 
@@ -953,8 +948,9 @@ int intel_crtc_set_crc_source(struct drm_crtc *crtc, const char *source_name,
 			g4x_undo_pipe_scramble_reset(dev_priv, crtc->index);
 		else if (IS_VALLEYVIEW(dev_priv) || IS_CHERRYVIEW(dev_priv))
 			vlv_undo_pipe_scramble_reset(dev_priv, crtc->index);
-		else if (IS_HASWELL(dev_priv) && crtc->index == PIPE_A)
-			hsw_trans_edp_pipe_A_crc_wa(dev_priv, false);
+		else if ((IS_HASWELL(dev_priv) ||
+			  IS_BROADWELL(dev_priv)) && crtc->index == PIPE_A)
+			hsw_pipe_A_crc_wa(dev_priv, false);
 
 		hsw_enable_ips(intel_crtc);
 	}