1 files changed, 87 insertions, 17 deletions

diff --git a/drivers/gpu/drm/i915/intel_pm.c b/drivers/gpu/drm/i915/intel_pm.c
index aea4cc2b3486..57c1dda76b94 100644
--- a/drivers/gpu/drm/i915/intel_pm.c
+++ b/drivers/gpu/drm/i915/intel_pm.c
@@ -3713,8 +3713,7 @@ skl_setup_sagv_block_time(struct drm_i915_private *dev_priv)
 		MISSING_CASE(DISPLAY_VER(dev_priv));
 	}
 
-	/* Default to an unusable block time */
-	dev_priv->sagv_block_time_us = -1;
+	dev_priv->sagv_block_time_us = 0;
 }
 
 /*
@@ -4020,6 +4019,17 @@ static int intel_compute_sagv_mask(struct intel_atomic_state *state)
 			return ret;
 	}
 
+	if (intel_can_enable_sagv(dev_priv, new_bw_state) !=
+	    intel_can_enable_sagv(dev_priv, old_bw_state)) {
+		ret = intel_atomic_serialize_global_state(&new_bw_state->base);
+		if (ret)
+			return ret;
+	} else if (new_bw_state->pipe_sagv_reject != old_bw_state->pipe_sagv_reject) {
+		ret = intel_atomic_lock_global_state(&new_bw_state->base);
+		if (ret)
+			return ret;
+	}
+
 	for_each_new_intel_crtc_in_state(state, crtc,
 					 new_crtc_state, i) {
 		struct skl_pipe_wm *pipe_wm = &new_crtc_state->wm.skl.optimal;
@@ -4035,17 +4045,6 @@ static int intel_compute_sagv_mask(struct intel_atomic_state *state)
 			intel_can_enable_sagv(dev_priv, new_bw_state);
 	}
 
-	if (intel_can_enable_sagv(dev_priv, new_bw_state) !=
-	    intel_can_enable_sagv(dev_priv, old_bw_state)) {
-		ret = intel_atomic_serialize_global_state(&new_bw_state->base);
-		if (ret)
-			return ret;
-	} else if (new_bw_state->pipe_sagv_reject != old_bw_state->pipe_sagv_reject) {
-		ret = intel_atomic_lock_global_state(&new_bw_state->base);
-		if (ret)
-			return ret;
-	}
-
 	return 0;
 }
 
@@ -4844,7 +4843,7 @@ static bool check_mbus_joined(u8 active_pipes,
 {
 	int i;
 
-	for (i = 0; i < dbuf_slices[i].active_pipes; i++) {
+	for (i = 0; dbuf_slices[i].active_pipes != 0; i++) {
 		if (dbuf_slices[i].active_pipes == active_pipes)
 			return dbuf_slices[i].join_mbus;
 	}
@@ -4861,7 +4860,7 @@ static u8 compute_dbuf_slices(enum pipe pipe, u8 active_pipes, bool join_mbus,
 {
 	int i;
 
-	for (i = 0; i < dbuf_slices[i].active_pipes; i++) {
+	for (i = 0; dbuf_slices[i].active_pipes != 0; i++) {
 		if (dbuf_slices[i].active_pipes == active_pipes &&
 		    dbuf_slices[i].join_mbus == join_mbus)
 			return dbuf_slices[i].dbuf_mask[pipe];
@@ -5635,7 +5634,7 @@ static void skl_compute_plane_wm(const struct intel_crtc_state *crtc_state,
 	result->min_ddb_alloc = max(min_ddb_alloc, blocks) + 1;
 	result->enable = true;
 
-	if (DISPLAY_VER(dev_priv) < 12)
+	if (DISPLAY_VER(dev_priv) < 12 && dev_priv->sagv_block_time_us)
 		result->can_sagv = latency >= dev_priv->sagv_block_time_us;
 }
 
@@ -5666,7 +5665,10 @@ static void tgl_compute_sagv_wm(const struct intel_crtc_state *crtc_state,
 	struct drm_i915_private *dev_priv = to_i915(crtc_state->uapi.crtc->dev);
 	struct skl_wm_level *sagv_wm = &plane_wm->sagv.wm0;
 	struct skl_wm_level *levels = plane_wm->wm;
-	unsigned int latency = dev_priv->wm.skl_latency[0] + dev_priv->sagv_block_time_us;
+	unsigned int latency = 0;
+
+	if (dev_priv->sagv_block_time_us)
+		latency = dev_priv->sagv_block_time_us + dev_priv->wm.skl_latency[0];
 
 	skl_compute_plane_wm(crtc_state, 0, latency,
 			     wm_params, &levels[0],
@@ -6681,6 +6683,74 @@ void skl_wm_get_hw_state(struct drm_i915_private *dev_priv)
 	dbuf_state->enabled_slices = dev_priv->dbuf.enabled_slices;
 }
 
+static bool skl_dbuf_is_misconfigured(struct drm_i915_private *i915)
+{
+	const struct intel_dbuf_state *dbuf_state =
+		to_intel_dbuf_state(i915->dbuf.obj.state);
+	struct skl_ddb_entry entries[I915_MAX_PIPES] = {};
+	struct intel_crtc *crtc;
+
+	for_each_intel_crtc(&i915->drm, crtc) {
+		const struct intel_crtc_state *crtc_state =
+			to_intel_crtc_state(crtc->base.state);
+
+		entries[crtc->pipe] = crtc_state->wm.skl.ddb;
+	}
+
+	for_each_intel_crtc(&i915->drm, crtc) {
+		const struct intel_crtc_state *crtc_state =
+			to_intel_crtc_state(crtc->base.state);
+		u8 slices;
+
+		slices = skl_compute_dbuf_slices(crtc, dbuf_state->active_pipes,
+						 dbuf_state->joined_mbus);
+		if (dbuf_state->slices[crtc->pipe] & ~slices)
+			return true;
+
+		if (skl_ddb_allocation_overlaps(&crtc_state->wm.skl.ddb, entries,
+						I915_MAX_PIPES, crtc->pipe))
+			return true;
+	}
+
+	return false;
+}
+
+void skl_wm_sanitize(struct drm_i915_private *i915)
+{
+	struct intel_crtc *crtc;
+
+	/*
+	 * On TGL/RKL (at least) the BIOS likes to assign the planes
+	 * to the wrong DBUF slices. This will cause an infinite loop
+	 * in skl_commit_modeset_enables() as it can't find a way to
+	 * transition between the old bogus DBUF layout to the new
+	 * proper DBUF layout without DBUF allocation overlaps between
+	 * the planes (which cannot be allowed or else the hardware
+	 * may hang). If we detect a bogus DBUF layout just turn off
+	 * all the planes so that skl_commit_modeset_enables() can
+	 * simply ignore them.
+	 */
+	if (!skl_dbuf_is_misconfigured(i915))
+		return;
+
+	drm_dbg_kms(&i915->drm, "BIOS has misprogrammed the DBUF, disabling all planes\n");
+
+	for_each_intel_crtc(&i915->drm, crtc) {
+		struct intel_plane *plane = to_intel_plane(crtc->base.primary);
+		const struct intel_plane_state *plane_state =
+			to_intel_plane_state(plane->base.state);
+		struct intel_crtc_state *crtc_state =
+			to_intel_crtc_state(crtc->base.state);
+
+		if (plane_state->uapi.visible)
+			intel_plane_disable_noatomic(crtc, plane);
+
+		drm_WARN_ON(&i915->drm, crtc_state->active_planes != 0);
+
+		memset(&crtc_state->wm.skl.ddb, 0, sizeof(crtc_state->wm.skl.ddb));
+	}
+}
+
 static void ilk_pipe_wm_get_hw_state(struct intel_crtc *crtc)
 {
 	struct drm_device *dev = crtc->base.dev;