[PATCH v4 0/2] ALPM rework and fixes

Jouni Högander jouni.hogander at intel.com
Tue May 13 05:48:12 UTC 2025


Currently there are couple of problems in ALPM implelementation:

1. ALPM registers are written while PSR/ Panel Replay is kept
   enabled. This is causing following error messages on PTL:
   
   "xe 0000:00:02.0: [drm] *ERROR* Timeout waiting for DDI BUF A to
   get active".

   This is fixed by enabling ALPM only once when needed.

2. ALPM is never disabled when used by PSR/Panel Replay. I.e. if PSR
   is once enabled ALPM is left enabled for good when PSR is
   disabled. This is fixed by using intel_alpm_disable and calling it
   for both cases: LOBF disable and PSR disable.

This patch set is addressing these.

v4:
  - do not add kerneldoc comments
  - improve comment on intel_psr_panel_replay_enable_sink call
v3:
  - enable/disable ALPM from PSR code
v2:
  - continue using rmw when disabling ALPM
  - take into account disabled hw in old_crtc_state

Jouni Högander (2):
  drm/i915/alpm: Make intel_alpm_enable_sink available for PSR
  drm/i915/alpm: Stop writing ALPM registers when PSR is enabled

 drivers/gpu/drm/i915/display/intel_alpm.c |  8 ++++----
 drivers/gpu/drm/i915/display/intel_alpm.h |  2 ++
 drivers/gpu/drm/i915/display/intel_psr.c  | 13 ++++++++++---
 3 files changed, 16 insertions(+), 7 deletions(-)

-- 
2.43.0



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