drm/i915: Make ips_enabled a property depending on whether IPS is enabled, v3.

ips_enabled was used as a variable of whether IPS can be enabled or not,
but should be used to test whether IPS is actually enabled.

Changes since v1:
- Call needs_modeset on new crtc state. (Ville)
- IPS can be enabled with sprite plane enabled too. (Ville)
- Fix CDCLK vs IPS workaround. (Ville)
Changes since v2:
- Only re-enable fastset when inheriting mode. (Ville)
- Put the conditions for enabling and disabling IPS in a helper.
Changes since v3:
- Keep the max_cdclk workaround working. (Ville)
- Also check logical cdclk out of paranoia.
- Remove planes check from IPS disable function for initial disable.
- Remove assert_plane_enabled/disabled checks and use
  crtc_state->active_planes for hsw_enable_ips only, always allow
  calling hsw_disable_ips to disable it initially in hw.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20171122183901.47720-1-maarten.lankhorst@linux.intel.com
[mlankhorst: pipe_config -> crtc_state (Ville)]
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>

drivers/gpu/drm/i915/intel_cdclk.c

@@ -1896,7 +1896,7 @@ int intel_crtc_compute_min_cdclk(const struct intel_crtc_state *crtc_state)
 	min_cdclk = intel_pixel_rate_to_cdclk(dev_priv, crtc_state->pixel_rate);
 
 	/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
-	if (IS_BROADWELL(dev_priv) && crtc_state->ips_enabled)
+	if (IS_BROADWELL(dev_priv) && hsw_crtc_state_ips_capable(crtc_state))
 		min_cdclk = DIV_ROUND_UP(min_cdclk * 100, 95);
 
 	/* BSpec says "Do not use DisplayPort with CDCLK less than 432 MHz,

drivers/gpu/drm/i915/intel_display.c

@@ -489,7 +489,7 @@ static const struct intel_limit intel_limits_bxt = {
 };
 
 static bool
-needs_modeset(struct drm_crtc_state *state)
+needs_modeset(const struct drm_crtc_state *state)
 {
 	return drm_atomic_crtc_needs_modeset(state);
 }
@@ -4833,7 +4833,7 @@ void hsw_enable_ips(const struct intel_crtc_state *crtc_state)
 	struct drm_device *dev = crtc->base.dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
 
-	if (!crtc->config->ips_enabled)
+	if (!crtc_state->ips_enabled)
 		return;
 
 	/*
@@ -4841,8 +4841,7 @@ void hsw_enable_ips(const struct intel_crtc_state *crtc_state)
 	 * This function is called from post_plane_update, which is run after
 	 * a vblank wait.
 	 */
-
-	assert_plane_enabled(to_intel_plane(crtc->base.primary));
+	WARN_ON(!(crtc_state->active_planes & ~BIT(PLANE_CURSOR)));
 
 	if (IS_BROADWELL(dev_priv)) {
 		mutex_lock(&dev_priv->pcu_lock);
@@ -4877,8 +4876,6 @@ void hsw_disable_ips(const struct intel_crtc_state *crtc_state)
 	if (!crtc_state->ips_enabled)
 		return;
 
-	assert_plane_enabled(to_intel_plane(crtc->base.primary));
-
 	if (IS_BROADWELL(dev_priv)) {
 		mutex_lock(&dev_priv->pcu_lock);
 		WARN_ON(sandybridge_pcode_write(dev_priv, DISPLAY_IPS_CONTROL, 0));
@@ -4931,14 +4928,6 @@ intel_post_enable_primary(struct drm_crtc *crtc,
 	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
 	int pipe = intel_crtc->pipe;
 
-	/*
-	 * FIXME IPS should be fine as long as one plane is
-	 * enabled, but in practice it seems to have problems
-	 * when going from primary only to sprite only and vice
-	 * versa.
-	 */
-	hsw_enable_ips(new_crtc_state);
-
 	/*
 	 * Gen2 reports pipe underruns whenever all planes are disabled.
 	 * So don't enable underrun reporting before at least some planes
@@ -4954,10 +4943,9 @@ intel_post_enable_primary(struct drm_crtc *crtc,
 	intel_check_pch_fifo_underruns(dev_priv);
 }
 
-/* FIXME move all this to pre_plane_update() with proper state tracking */
+/* FIXME get rid of this and use pre_plane_update */
 static void
-intel_pre_disable_primary(struct drm_crtc *crtc,
-			  const struct intel_crtc_state *old_crtc_state)
+intel_pre_disable_primary_noatomic(struct drm_crtc *crtc)
 {
 	struct drm_device *dev = crtc->dev;
 	struct drm_i915_private *dev_priv = to_i915(dev);
@@ -4966,32 +4954,12 @@ intel_pre_disable_primary(struct drm_crtc *crtc,
 
 	/*
 	 * Gen2 reports pipe underruns whenever all planes are disabled.
-	 * So diasble underrun reporting before all the planes get disabled.
-	 * FIXME: Need to fix the logic to work when we turn off all planes
-	 * but leave the pipe running.
+	 * So disable underrun reporting before all the planes get disabled.
 	 */
 	if (IS_GEN2(dev_priv))
 		intel_set_cpu_fifo_underrun_reporting(dev_priv, pipe, false);
 
-	/*
-	 * FIXME IPS should be fine as long as one plane is
-	 * enabled, but in practice it seems to have problems
-	 * when going from primary only to sprite only and vice
-	 * versa.
-	 */
-	hsw_disable_ips(old_crtc_state);
-}
-
-/* FIXME get rid of this and use pre_plane_update */
-static void
-intel_pre_disable_primary_noatomic(struct drm_crtc *crtc)
-{
-	struct drm_device *dev = crtc->dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
-	struct intel_crtc *intel_crtc = to_intel_crtc(crtc);
-	int pipe = intel_crtc->pipe;
-
-	intel_pre_disable_primary(crtc, to_intel_crtc_state(crtc->state));
+	hsw_disable_ips(to_intel_crtc_state(crtc->state));
 
 	/*
 	 * Vblank time updates from the shadow to live plane control register
@@ -5007,6 +4975,38 @@ intel_pre_disable_primary_noatomic(struct drm_crtc *crtc)
 		intel_wait_for_vblank(dev_priv, pipe);
 }
 
+static bool hsw_pre_update_disable_ips(const struct intel_crtc_state *old_crtc_state,
+				       const struct intel_crtc_state *new_crtc_state)
+{
+	if (!old_crtc_state->ips_enabled)
+		return false;
+
+	if (needs_modeset(&new_crtc_state->base))
+		return true;
+
+	return !new_crtc_state->ips_enabled;
+}
+
+static bool hsw_post_update_enable_ips(const struct intel_crtc_state *old_crtc_state,
+				       const struct intel_crtc_state *new_crtc_state)
+{
+	if (!new_crtc_state->ips_enabled)
+		return false;
+
+	if (needs_modeset(&new_crtc_state->base))
+		return true;
+
+	/*
+	 * We can't read out IPS on broadwell, assume the worst and
+	 * forcibly enable IPS on the first fastset.
+	 */
+	if (new_crtc_state->update_pipe &&
+	    old_crtc_state->base.adjusted_mode.private_flags & I915_MODE_FLAG_INHERITED)
+		return true;
+
+	return !old_crtc_state->ips_enabled;
+}
+
 static void intel_post_plane_update(struct intel_crtc_state *old_crtc_state)
 {
 	struct intel_crtc *crtc = to_intel_crtc(old_crtc_state->base.crtc);
@@ -5023,6 +5023,9 @@ static void intel_post_plane_update(struct intel_crtc_state *old_crtc_state)
 	if (pipe_config->update_wm_post && pipe_config->base.active)
 		intel_update_watermarks(crtc);
 
+	if (hsw_post_update_enable_ips(old_crtc_state, pipe_config))
+		hsw_enable_ips(pipe_config);
+
 	if (old_pri_state) {
 		struct intel_plane_state *primary_state =
 			intel_atomic_get_new_plane_state(to_intel_atomic_state(old_state),
@@ -5053,6 +5056,9 @@ static void intel_pre_plane_update(struct intel_crtc_state *old_crtc_state,
 	struct intel_atomic_state *old_intel_state =
 		to_intel_atomic_state(old_state);
 
+	if (hsw_pre_update_disable_ips(old_crtc_state, pipe_config))
+		hsw_disable_ips(old_crtc_state);
+
 	if (old_pri_state) {
 		struct intel_plane_state *primary_state =
 			intel_atomic_get_new_plane_state(old_intel_state,
@@ -5061,10 +5067,13 @@ static void intel_pre_plane_update(struct intel_crtc_state *old_crtc_state,
 			to_intel_plane_state(old_pri_state);
 
 		intel_fbc_pre_update(crtc, pipe_config, primary_state);
-
-		if (old_primary_state->base.visible &&
+		/*
+		 * Gen2 reports pipe underruns whenever all planes are disabled.
+		 * So disable underrun reporting before all the planes get disabled.
+		 */
+		if (IS_GEN2(dev_priv) && old_primary_state->base.visible &&
 		    (modeset || !primary_state->base.visible))
-			intel_pre_disable_primary(&crtc->base, old_crtc_state);
+			intel_set_cpu_fifo_underrun_reporting(dev_priv, crtc->pipe, false);
 	}
 
 	/*
@@ -6195,18 +6204,20 @@ retry:
 	return ret;
 }
 
-static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
-				     struct intel_crtc_state *pipe_config)
+bool hsw_crtc_state_ips_capable(const struct intel_crtc_state *crtc_state)
 {
-	if (pipe_config->ips_force_disable)
+	struct intel_crtc *crtc = to_intel_crtc(crtc_state->base.crtc);
+	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
+
+	/* IPS only exists on ULT machines and is tied to pipe A. */
+	if (!hsw_crtc_supports_ips(crtc))
 		return false;
 
-	if (pipe_config->pipe_bpp > 24)
+	if (!i915_modparams.enable_ips)
 		return false;
 
-	/* HSW can handle pixel rate up to cdclk? */
-	if (IS_HASWELL(dev_priv))
-		return true;
+	if (crtc_state->pipe_bpp > 24)
+		return false;
 
 	/*
 	 * We compare against max which means we must take
@@ -6215,19 +6226,41 @@ static bool pipe_config_supports_ips(struct drm_i915_private *dev_priv,
 	 *
 	 * Should measure whether using a lower cdclk w/o IPS
 	 */
-	return pipe_config->pixel_rate <=
-		dev_priv->max_cdclk_freq * 95 / 100;
+	if (IS_BROADWELL(dev_priv) &&
+	    crtc_state->pixel_rate > dev_priv->max_cdclk_freq * 95 / 100)
+		return false;
+
+	return true;
 }
 
-static void hsw_compute_ips_config(struct intel_crtc *crtc,
-				   struct intel_crtc_state *pipe_config)
+static bool hsw_compute_ips_config(struct intel_crtc_state *crtc_state)
 {
-	struct drm_device *dev = crtc->base.dev;
-	struct drm_i915_private *dev_priv = to_i915(dev);
+	struct drm_i915_private *dev_priv =
+		to_i915(crtc_state->base.crtc->dev);
+	struct intel_atomic_state *intel_state =
+		to_intel_atomic_state(crtc_state->base.state);
 
-	pipe_config->ips_enabled = i915_modparams.enable_ips &&
-		hsw_crtc_supports_ips(crtc) &&
-		pipe_config_supports_ips(dev_priv, pipe_config);
+	if (!hsw_crtc_state_ips_capable(crtc_state))
+		return false;
+
+	if (crtc_state->ips_force_disable)
+		return false;
+
+	/*
+	 * FIXME IPS should be fine as long as one plane is
+	 * enabled, but in practice it seems to have problems
+	 * when going from primary only to sprite only and vice
+	 * versa.
+	 */
+	if (!(crtc_state->active_planes & BIT(PLANE_PRIMARY)))
+		return false;
+
+	/* pixel rate mustn't exceed 95% of cdclk with IPS on BDW */
+	if (IS_BROADWELL(dev_priv) &&
+	    crtc_state->pixel_rate > intel_state->cdclk.logical.cdclk * 95 / 100)
+		return false;
+
+	return true;
 }
 
 static bool intel_crtc_supports_double_wide(const struct intel_crtc *crtc)
@@ -6345,9 +6378,6 @@ static int intel_crtc_compute_config(struct intel_crtc *crtc,
 
 	intel_crtc_compute_pixel_rate(pipe_config);
 
-	if (HAS_IPS(dev_priv))
-		hsw_compute_ips_config(crtc, pipe_config);
-
 	if (pipe_config->has_pch_encoder)
 		return ironlake_fdi_compute_config(crtc, pipe_config);
 
@@ -9183,6 +9213,19 @@ static bool haswell_get_pipe_config(struct intel_crtc *crtc,
 			ironlake_get_pfit_config(crtc, pipe_config);
 	}
 
+	if (hsw_crtc_supports_ips(crtc)) {
+		if (IS_HASWELL(dev_priv))
+			pipe_config->ips_enabled = I915_READ(IPS_CTL) & IPS_ENABLE;
+		else {
+			/*
+			 * We cannot readout IPS state on broadwell, set to
+			 * true so we can set it to a defined state on first
+			 * commit.
+			 */
+			pipe_config->ips_enabled = true;
+		}
+	}
+
 	if (pipe_config->cpu_transcoder != TRANSCODER_EDP &&
 	    !transcoder_is_dsi(pipe_config->cpu_transcoder)) {
 		pipe_config->pixel_multiplier =
@@ -10435,6 +10478,9 @@ static int intel_crtc_atomic_check(struct drm_crtc *crtc,
 							 pipe_config);
 	}
 
+	if (HAS_IPS(dev_priv))
+		pipe_config->ips_enabled = hsw_compute_ips_config(pipe_config);
+
 	return ret;
 }
 

drivers/gpu/drm/i915/intel_drv.h

@@ -1488,6 +1488,7 @@ bool bxt_find_best_dpll(struct intel_crtc_state *crtc_state, int target_clock,
 int chv_calc_dpll_params(int refclk, struct dpll *pll_clock);
 
 bool intel_crtc_active(struct intel_crtc *crtc);
+bool hsw_crtc_state_ips_capable(const struct intel_crtc_state *crtc_state);
 void hsw_enable_ips(const struct intel_crtc_state *crtc_state);
 void hsw_disable_ips(const struct intel_crtc_state *crtc_state);
 enum intel_display_power_domain intel_port_to_power_domain(enum port port);

drivers/gpu/drm/i915/intel_pipe_crc.c

@@ -541,8 +541,6 @@ retry:
 		 * 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)) {