On 12/23/2025 4:21 PM, Jouni Högander wrote:
We are planning to move using trans push mechanism to trigger the Frame
Change event. in that case we can't wait PSR to idle before send push
happens. Due to this move wait for idle to be done after possible send push
is done.
This should be ok for Frame Change event triggered by register write as
well. Wait for idle is needed only for corner case where PSR is
transitioning into DEEP_SLEEP when Frame Change event is triggered. It just
has to be before wait for vblank. Otherwise we may have vblank before PSR
enters DEEP_SLEEP and still using old frame buffers for first frame after
wake up.
Signed-off-by: Jouni Högander <[email protected]>
---
drivers/gpu/drm/i915/display/intel_display.c | 13 ++++++++++---
1 file changed, 10 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/display/intel_display.c
b/drivers/gpu/drm/i915/display/intel_display.c
index c7ca4f53b8b8..1aca4802b7d5 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7333,9 +7333,6 @@ static void intel_atomic_dsb_finish(struct
intel_atomic_state *state,
intel_psr_trigger_frame_change_event(new_crtc_state->dsb_commit,
state, crtc);
- intel_psr_wait_for_idle_dsb(new_crtc_state->dsb_commit,
- new_crtc_state);
-
if (new_crtc_state->use_dsb)
intel_dsb_vblank_evade(state,
new_crtc_state->dsb_commit);
@@ -7375,6 +7372,16 @@ static void intel_atomic_dsb_finish(struct intel_atomic_state *state,
intel_vrr_send_push(new_crtc_state->dsb_commit, new_crtc_state);
+ /*
+ * Wait for idle is needed for corner case where PSR HW
+ * is transitioning into DEEP_SLEEP/SRDENT_OFF when
+ * new Frame Change event comes in. It is ok to do it
+ * here for both Frame Change mecanisms (trans push
+ * and register write).
+ */
+ intel_psr_wait_for_idle_dsb(new_crtc_state->dsb_commit,
+ new_crtc_state);
+
If I understand correctly:
For Fixed RR case:
Suppose we are in PSR:
Skip_wait_en is set.
The portion around the Send Push will be like:
-dsb_wait_vblank will no longer wait for the undelayed vblank (we are in
PSR and skip_wait_en is set)
-we send push -> to trigger frame change event for PSR HW.
-After this PSR HW is supposed to receive the event and may be in
transition period so we wait for idle dsb.(which internally makes sure
that we are out of PSR)
-We are not sure whether we are in active or in vblank region at this
point of time so we want to use dsb_wait_vblank. The skip_wait_en will
now not come in picture since we have made sure that we are not in PSR
in previous step.
Then other steps will be similar to what we have been doing.
Is my understanding correct?
What happens when Panel Replay is in picture, given we can have PR
enable with Variable Refresh Rate timings.
Regards,
Ankit
/*
* In case PSR uses trans push as a "frame change" event and
* VRR is not in use we need to wait vblank. Othervise we may
