[Intel-gfx] [PATCH v4 1/2] drm/i915/psr: Use full update In case of area calculation fails

[Jouni Högander]

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

Cc: José Roberto de Souza <jose.souza at intel.com>
Cc: Mika Kahola <mika.kahola at intel.com>
Signed-off-by: Jouni Högander <jouni.hogander at intel.com>
---
 drivers/gpu/drm/i915/display/intel_psr.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_psr.c b/drivers/gpu/drm/i915/display/intel_psr.c
index 06db407e2749..1f031ebc1456 100644
--- a/drivers/gpu/drm/i915/display/intel_psr.c
+++ b/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 +1771,17 @@ 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 pipeA");
+		full_update = true;
+	}
+
 	if (full_update)
 		goto skip_sel_fetch_set_loop;
 
-- 
2.25.1