drm/i915: Track active_pipes in bw_state

We need to calculate SAGV mask also in a non-modeset
commit, however currently active_pipes are only calculated
for modesets in global atomic state, thus now we will be
tracking those also in bw_state in order to be able to
properly access global data.

v2: - Removed pre/post plane SAGV updates from modeset(Ville)
    - Now tracking active pipes in intel_can_enable_sagv(Ville)

v3: - lock global state if active_pipes change as well(Ville)

Signed-off-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200430195634.7666-1-stanislav.lisovskiy@intel.com

drivers/gpu/drm/i915/display/intel_bw.h

@@ -26,6 +26,9 @@ struct intel_bw_state {
 
 	unsigned int data_rate[I915_MAX_PIPES];
 	u8 num_active_planes[I915_MAX_PIPES];
+
+	/* bitmask of active pipes */
+	u8 active_pipes;
 };
 
 #define to_intel_bw_state(x) container_of((x), struct intel_bw_state, base)

drivers/gpu/drm/i915/display/intel_display.c

@@ -15379,11 +15379,11 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 
 		intel_set_cdclk_pre_plane_update(state);
 
-		intel_sagv_pre_plane_update(state);
-
 		intel_modeset_verify_disabled(dev_priv, state);
 	}
 
+	intel_sagv_pre_plane_update(state);
+
 	/* Complete the events for pipes that have now been disabled */
 	for_each_new_intel_crtc_in_state(state, crtc, new_crtc_state, i) {
 		bool modeset = needs_modeset(new_crtc_state);
@@ -15476,11 +15476,10 @@ static void intel_atomic_commit_tail(struct intel_atomic_state *state)
 	intel_check_cpu_fifo_underruns(dev_priv);
 	intel_check_pch_fifo_underruns(dev_priv);
 
-	if (state->modeset) {
+	if (state->modeset)
 		intel_verify_planes(state);
 
-		intel_sagv_post_plane_update(state);
-	}
+	intel_sagv_post_plane_update(state);
 
 	drm_atomic_helper_commit_hw_done(&state->base);
 

drivers/gpu/drm/i915/intel_pm.c

@@ -3806,7 +3806,6 @@ void intel_sagv_post_plane_update(struct intel_atomic_state *state)
 
 static bool intel_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state)
 {
-	struct intel_atomic_state *state = to_intel_atomic_state(crtc_state->uapi.state);
 	struct intel_crtc *crtc = to_intel_crtc(crtc_state->uapi.crtc);
 	struct drm_i915_private *dev_priv = to_i915(crtc->base.dev);
 	struct intel_plane *plane;
@@ -3819,13 +3818,6 @@ static bool intel_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state
 	if (!crtc_state->hw.active)
 		return true;
 
-	/*
-	 * SKL+ workaround: bspec recommends we disable SAGV when we have
-	 * more then one pipe enabled
-	 */
-	if (hweight8(state->active_pipes) > 1)
-		return false;
-
 	if (crtc_state->hw.adjusted_mode.flags & DRM_MODE_FLAG_INTERLACE)
 		return false;
 
@@ -3863,6 +3855,9 @@ static bool intel_crtc_can_enable_sagv(const struct intel_crtc_state *crtc_state
 
 bool intel_can_enable_sagv(const struct intel_bw_state *bw_state)
 {
+	if (bw_state->active_pipes && !is_power_of_2(bw_state->active_pipes))
+		return false;
+
 	return bw_state->pipe_sagv_reject == 0;
 }
 
@@ -3892,6 +3887,14 @@ static int intel_compute_sagv_mask(struct intel_atomic_state *state)
 	if (!new_bw_state)
 		return 0;
 
+	new_bw_state->active_pipes =
+		intel_calc_active_pipes(state, old_bw_state->active_pipes);
+	if (new_bw_state->active_pipes != old_bw_state->active_pipes) {
+		ret = intel_atomic_lock_global_state(&new_bw_state->base);
+		if (ret)
+			return ret;
+	}
+
 	if (intel_can_enable_sagv(new_bw_state) != intel_can_enable_sagv(old_bw_state)) {
 		ret = intel_atomic_serialize_global_state(&new_bw_state->base);
 		if (ret)
@@ -5866,11 +5869,9 @@ skl_compute_wm(struct intel_atomic_state *state)
 	if (ret)
 		return ret;
 
-	if (state->modeset) {
-		ret = intel_compute_sagv_mask(state);
-		if (ret)
-			return ret;
-	}
+	ret = intel_compute_sagv_mask(state);
+	if (ret)
+		return ret;
 
 	/*
 	 * skl_compute_ddb() will have adjusted the final watermarks