FBC was disabled in case PSR2 selective update in display 12 to
14 as part of a wa. From xe2lpd onwards there is a logic to be
implemented to decide between FBC and selective update. Until
that logic is implemented keep FBC disabled in case selective
update is enabled.

v1: updated patch description and some explanation and todo

Signed-off-by: Vinod Govindapillai <[email protected]>
---
 drivers/gpu/drm/i915/display/intel_fbc.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/display/intel_fbc.c 
b/drivers/gpu/drm/i915/display/intel_fbc.c
index b6978135e8ad..92b00da4c0ab 100644
--- a/drivers/gpu/drm/i915/display/intel_fbc.c
+++ b/drivers/gpu/drm/i915/display/intel_fbc.c
@@ -1464,13 +1464,15 @@ static int intel_fbc_check_plane(struct 
intel_atomic_state *state,
         * Recommendation is to keep this combination disabled
         * Bspec: 50422 HSD: 14010260002
         *
-        * In Xe3, PSR2 selective fetch and FBC dirty rect feature cannot
-        * coexist. So if PSR2 selective fetch is supported then mark that
-        * FBC is not supported.
-        * TODO: Need a logic to decide between PSR2 and FBC Dirty rect
+        * TODO: Implement a logic to select between PSR2 selective fetch and
+        * FBC based on Bspec: 68881 in xe2lpd onwards.
+        *
+        * As we still see some strange underruns in those platforms while
+        * disabling PSR2, keep FBC disabled in case of selective update is on
+        * until the selection logic is implemented.
         */
-       if ((IS_DISPLAY_VER(display, 12, 14) || HAS_FBC_DIRTY_RECT(display)) &&
-           crtc_state->has_sel_update && !crtc_state->has_panel_replay) {
+       if (DISPLAY_VER(display) >= 12 && crtc_state->has_sel_update &&
+           !crtc_state->has_panel_replay) {
                plane_state->no_fbc_reason = "PSR2 enabled";
                return 0;
        }
-- 
2.43.0

Reply via email to