drm/i915/psr: Use full update In case of area calculation fails

Currently we have some corner cases where area calculation fails.  For
these sel fetch area calculation ends up having update area as y1 = 0,
y2 = 4. Instead of these values safer option is full update.

One of such for example is big fb with offset. We don't have usable
offset in psr2_sel_fetch_update. Currently it's open what is the
proper way to fix this corner case. Use full update for now.

v2: Commit message modified
v3: Print out debug info once when area calculation fails
v4: Use drm_info_once
v5: pipeA -> "pipe %c", pipe_name(crtc-pipe)

Cc: José Roberto de Souza <jose.souza@intel.com>
Cc: Mika Kahola <mika.kahola@intel.com>
Signed-off-by: Jouni Högander <jouni.hogander@intel.com>
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Signed-off-by: José Roberto de Souza <jose.souza@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220513142811.779331-2-jouni.hogander@intel.com

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

@@ -1685,6 +1685,7 @@ static bool psr2_sel_fetch_pipe_state_supported(const struct intel_crtc_state *c
 int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 				struct intel_crtc *crtc)
 {
+	struct drm_i915_private *dev_priv = to_i915(state->base.dev);
 	struct intel_crtc_state *crtc_state = intel_atomic_get_new_crtc_state(state, crtc);
 	struct drm_rect pipe_clip = { .x1 = 0, .y1 = -1, .x2 = INT_MAX, .y2 = -1 };
 	struct intel_plane_state *new_plane_state, *old_plane_state;
@@ -1770,6 +1771,19 @@ int intel_psr2_sel_fetch_update(struct intel_atomic_state *state,
 		clip_area_update(&pipe_clip, &damaged_area);
 	}
 
+	/*
+	 * TODO: For now we are just using full update in case
+	 * selective fetch area calculation fails. To optimize this we
+	 * should identify cases where this happens and fix the area
+	 * calculation for those.
+	 */
+	if (pipe_clip.y1 == -1) {
+		drm_info_once(&dev_priv->drm,
+			      "Selective fetch area calculation failed in pipe %c\n",
+			      pipe_name(crtc->pipe));
+		full_update = true;
+	}
+
 	if (full_update)
 		goto skip_sel_fetch_set_loop;