[PATCH v10 00/10] Use trans push mechanism to generate frame change event

Jouni Högander
2026-01-26T08:00:34Z

Currently we are using "automatic" frame change event generation. The
event is generated by any access to plane or pipe registers.

We have option to use "PSR PR Frame Change Enable" bit in TRANS_PUSH
register to enable frame change event generation only when doing trans
push. When this bit is set "automatic" frame change event generation
doesn't work anymore. Benfit from this is more controled updates send
by PSR HW.

This patch set is taking trans push mechanism into use.

v10:
- added patch implementing helper for parsing value to be written
into TRANS_PUSH
- Adding HAS_PSR_FRAME_CHANGE macro moved to separate patch and
renamed as HAS_PSR_TRANS_PUSH_FRAME_CHANGE
- use intel_psr_use_trans_push instead of HAS_PSR_FRAME_CHANGE in
intel_psr_trigger_frame_change
- moved calling intel_vrr_psr_frame_change_enable away from this
patch
-
v9: always do PSR exit on frontbuffer flush for LunarLake and onwards
v8:
- rebase
- Wait for idle only after possible send
v7:
- added bspec references
- add HAS_PSR_FRAME_CHANGE macro
- use TRANS_PUSH in instead of TRAN_VRR_CTL
- "Do not trigger Frame Change events from frontbuffer flush" patch
already merged
v6: use AND instead of OR in intel_psr_use_trans_push
v5: add missing patch
v4:
- add intel_psr_use_trans_push to query if TRANS_PUSH is used
- set DSB_SKIP_WAITS_EN chicken bit when TRANS_PUSH is used
- Wait for vblank in case of PSR is using trans push
v3:
- use rmw when enabling disabling transh push for PSR or VRR
- rely on crtc_state->has_psr/has_vrr to keep trans push enabled
- modify frontbuffer flush/invalidate to use disable/enable also for
SU/SF on recent platforms.
- send push before waiting for vblank
v2: implement intel_vrr_trans_push_enabled_set_clear and use that
instead of rmw

Jouni Högander (10):
drm/i915/psr: Add TRANS_PUSH register bit definition for PSR
drm/i915/psr: Add intel_psr_use_trans_push to query if TRANS_PUSH is
used
drm/i915/vrr: Add helper for parsing value to be written into
TRANS_PUSH
drm/i915/vrr: Prepare to Use TRANS_PUSH mechanism for PSR frame change
drm/i915/dsb: Set DSB_SKIP_WAITS_EN chicken bit for LunarLake and
onwards
drm/i915/display: Wait for vblank in case of PSR is using trans push
drm/i915/psr: Wait for idle only after possible send push
drm/i915/psr: Do PSR exit on frontbuffer flush on LunarLake and
onwards
drm/i915/display: Add HAS_PSR_TRANS_PUSH_FRAME_CHANGE macro
drm/i915/psr: Use TRANS_PUSH to trigger frame change event

drivers/gpu/drm/i915/display/intel_crtc.c | 4 +-
drivers/gpu/drm/i915/display/intel_display.c | 33 ++++++++++++++--
.../drm/i915/display/intel_display_device.h | 1 +
drivers/gpu/drm/i915/display/intel_dsb.c | 15 +++++--
drivers/gpu/drm/i915/display/intel_psr.c | 36 +++++++++++------
drivers/gpu/drm/i915/display/intel_psr.h | 1 +
drivers/gpu/drm/i915/display/intel_vrr.c | 39 ++++++++++++++++---
drivers/gpu/drm/i915/display/intel_vrr.h | 1 +
drivers/gpu/drm/i915/display/intel_vrr_regs.h | 1 +
9 files changed, 106 insertions(+), 25 deletions(-)

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2.43.0