drm/i915: implement async_flip mode per plane tracking

Current implementation of async flip w/a relies on assumption that
previous atomic commit contains valid information if async_flip is still
enabled on the plane. It is incorrect. If previous commit did not modify
the plane its state->uapi.async_flip can be false. As a result DMAR/PIPE
errors can be observed:
i915 0000:00:02.0: [drm] *ERROR* Fault errors on pipe A: 0x00000080
i915 0000:00:02.0: [drm] *ERROR* Fault errors on pipe A: 0x00000080
DMAR: DRHD: handling fault status reg 2
DMAR: [DMA Read NO_PASID] Request device [00:02.0] fault addr 0x0 [fault reason 0x06] PTE Read access is not set

v2: update async_flip_planes in more reliable places (Ville)
v3: reset async_flip_planes and do_async_flip in more scenarios (Ville)
v4: move all resets to plane loops (Ville)
Signed-off-by: Andrzej Hajda <andrzej.hajda@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230127153003.2225111-1-andrzej.hajda@intel.com

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

@@ -363,6 +363,7 @@ void intel_plane_set_invisible(struct intel_crtc_state *crtc_state,
 	crtc_state->scaled_planes &= ~BIT(plane->id);
 	crtc_state->nv12_planes &= ~BIT(plane->id);
 	crtc_state->c8_planes &= ~BIT(plane->id);
+	crtc_state->async_flip_planes &= ~BIT(plane->id);
 	crtc_state->data_rate[plane->id] = 0;
 	crtc_state->data_rate_y[plane->id] = 0;
 	crtc_state->rel_data_rate[plane->id] = 0;
@@ -582,8 +583,10 @@ static int intel_plane_atomic_calc_changes(const struct intel_crtc_state *old_cr
 			 intel_plane_is_scaled(new_plane_state))))
 		new_crtc_state->disable_lp_wm = true;
 
-	if (intel_plane_do_async_flip(plane, old_crtc_state, new_crtc_state))
+	if (intel_plane_do_async_flip(plane, old_crtc_state, new_crtc_state)) {
 		new_crtc_state->do_async_flip = true;
+		new_crtc_state->async_flip_planes |= BIT(plane->id);
+	}
 
 	return 0;
 }

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

@@ -1500,6 +1500,8 @@ intel_color_add_affected_planes(struct intel_crtc_state *new_crtc_state)
 			return PTR_ERR(plane_state);
 
 		new_crtc_state->update_planes |= BIT(plane->id);
+		new_crtc_state->async_flip_planes = 0;
+		new_crtc_state->do_async_flip = false;
 
 		/* plane control register changes blocked by CxSR */
 		if (HAS_GMCH(i915))

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

@@ -1252,7 +1252,8 @@ static void intel_crtc_async_flip_disable_wa(struct intel_atomic_state *state,
 		intel_atomic_get_old_crtc_state(state, crtc);
 	const struct intel_crtc_state *new_crtc_state =
 		intel_atomic_get_new_crtc_state(state, crtc);
-	u8 update_planes = new_crtc_state->update_planes;
+	u8 disable_async_flip_planes = old_crtc_state->async_flip_planes &
+				       ~new_crtc_state->async_flip_planes;
 	const struct intel_plane_state *old_plane_state;
 	struct intel_plane *plane;
 	bool need_vbl_wait = false;
@@ -1261,7 +1262,7 @@ static void intel_crtc_async_flip_disable_wa(struct intel_atomic_state *state,
 	for_each_old_intel_plane_in_state(state, plane, old_plane_state, i) {
 		if (plane->need_async_flip_disable_wa &&
 		    plane->pipe == crtc->pipe &&
-		    update_planes & BIT(plane->id)) {
+		    disable_async_flip_planes & BIT(plane->id)) {
 			/*
 			 * Apart from the async flip bit we want to
 			 * preserve the old state for the plane.
@@ -1378,7 +1379,7 @@ static void intel_pre_plane_update(struct intel_atomic_state *state,
 	 * WA for platforms where async address update enable bit
 	 * is double buffered and only latched at start of vblank.
 	 */
-	if (old_crtc_state->uapi.async_flip && !new_crtc_state->uapi.async_flip)
+	if (old_crtc_state->async_flip_planes & ~new_crtc_state->async_flip_planes)
 		intel_crtc_async_flip_disable_wa(state, crtc);
 }
 
@@ -5939,6 +5940,8 @@ int intel_modeset_all_pipes(struct intel_atomic_state *state,
 			return ret;
 
 		crtc_state->update_planes |= crtc_state->active_planes;
+		crtc_state->async_flip_planes = 0;
+		crtc_state->do_async_flip = false;
 	}
 
 	return 0;

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

@@ -1249,6 +1249,9 @@ struct intel_crtc_state {
 	/* bitmask of planes that will be updated during the commit */
 	u8 update_planes;
 
+	/* bitmask of planes with async flip active */
+	u8 async_flip_planes;
+
 	u8 framestart_delay; /* 1-4 */
 	u8 msa_timing_delay; /* 0-3 */
 

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

@@ -2397,6 +2397,8 @@ skl_ddb_add_affected_planes(const struct intel_crtc_state *old_crtc_state,
 			return PTR_ERR(plane_state);
 
 		new_crtc_state->update_planes |= BIT(plane_id);
+		new_crtc_state->async_flip_planes = 0;
+		new_crtc_state->do_async_flip = false;
 	}
 
 	return 0;
@@ -2754,6 +2756,8 @@ static int skl_wm_add_affected_planes(struct intel_atomic_state *state,
 			return PTR_ERR(plane_state);
 
 		new_crtc_state->update_planes |= BIT(plane_id);
+		new_crtc_state->async_flip_planes = 0;
+		new_crtc_state->do_async_flip = false;
 	}
 
 	return 0;