We may have commit which doesn't have any non-arming plane register
writes. In that case there aren't "Frame Change" event before DSB vblank
evasion which hangs as PIPEDSL register is reading as 0 when PSR state is
SRDENT(PSR1) or DEEP_SLEEP(PSR2). Handle this by adding dummy write
triggering the "Frame Change" event.

Signed-off-by: Jouni Högander <[email protected]>
---
 drivers/gpu/drm/i915/display/intel_display.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_display.c 
b/drivers/gpu/drm/i915/display/intel_display.c
index a189aa437d972..cd7e960bd29f1 100644
--- a/drivers/gpu/drm/i915/display/intel_display.c
+++ b/drivers/gpu/drm/i915/display/intel_display.c
@@ -7666,6 +7666,7 @@ static void intel_atomic_dsb_finish(struct 
intel_atomic_state *state,
                intel_atomic_get_old_crtc_state(state, crtc);
        struct intel_crtc_state *new_crtc_state =
                intel_atomic_get_new_crtc_state(state, crtc);
+       struct intel_display *display = to_intel_display(crtc);
 
        if (!new_crtc_state->hw.active)
                return;
@@ -7708,6 +7709,15 @@ static void intel_atomic_dsb_finish(struct 
intel_atomic_state *state,
                intel_crtc_planes_update_noarm(new_crtc_state->dsb_commit,
                                               state, crtc);
 
+               /*
+                * Ensure we have "Frame Change" event when PSR state is
+                * SRDENT(PSR1) or DEEP_SLEEP(PSR2). Otherwise DSB vblank
+                * evasion hangs as PIPEDSL is reading as 0.
+                */
+               if (new_crtc_state->has_psr && 
!new_crtc_state->has_panel_replay)
+                       intel_de_write_dsb(display, new_crtc_state->dsb_commit,
+                                          CURSURFLIVE(display, crtc->pipe), 0);
+
                intel_dsb_vblank_evade(state, new_crtc_state->dsb_commit);
 
                if (intel_crtc_needs_color_update(new_crtc_state))
-- 
2.43.0

Reply via email to