ACK: [SRU][Q][PATCH 0/5] Fix for i915 PSR issue on SDC panels on Intel PTL

[Masahiro Yamada]

On 3/18/26 14:57, Aaron Ma wrote:
> BugLink: https://bugs.launchpad.net/bugs/2144637
>
> [Impact]
> After suspend/resume, the internal display freezes and stops refreshing on
> systems with SDC eDP panels using Panel Replay. The display content appears
> frozen — typing or mouse movement shows no visual feedback. External
> monitors continue to work normally.
>
> The root cause is incorrect handling of Panel Replay Selective Update X
> granularity DPCD registers (0xb2 and 0xb3). Per the DP specification,
> 0xffff means full-line granularity, but the driver did not handle this
> special value, causing selective update to fail after suspend/resume.
>
> Upstream bug: https://gitlab.freedesktop.org/drm/xe/kernel/-/issues/7284
>
> [Fix]
> Cherry-pick 5 upstream commits (v6.18 through v7.0-rc3):
>
> - f861e54fb33b5 ("drm/i915/psr: Add panel granularity information into intel_connector")
> - 90d8aad11f613 ("drm/i915/psr: Panel Replay SU cap dpcd read return value")
> - 1cc854647450  ("drm/i915/psr: Use SU granularity information available in intel_connector")
> - ace7dcc818137 ("drm/dp: Add definition for Panel Replay full-line granularity")
> - a99cac460ddeb ("drm/i915/psr: Fix for Panel Replay X granularity DPCD register handling")
>
> [Test Plan]
> On a system with an SDC eDP panel supporting Panel Replay:
>
> $ for i in $(seq 1 10); do sudo rtcwake -m mem -s 20; sleep 5; done
>
> Without the patch: Internal display freezes after resume.
> With the patch: Display refreshes normally after every resume.
>
> [Where problems could occur]
> Incorrect granularity handling could cause visual artifacts on panels with
> non-0xffff granularity values. All patches are upstream and reviewed by
> Intel display maintainers.
>
> [Other Info]
> SRU for OEM-6.17, questing, and resolute.
>
> Jouni Högander (5):
>    drm/i915/psr: Panel Replay SU cap dpcd read return value
>    drm/i915/psr: Add panel granularity information into intel_connector
>    drm/i915/psr: Use SU granularity information available in
>      intel_connector
>    drm/dp: Add definition for Panel Replay full-line granularity
>    drm/i915/psr: Fix for Panel Replay X granularity DPCD register
>      handling
>
>   .../drm/i915/display/intel_display_types.h    |  10 ++
>   drivers/gpu/drm/i915/display/intel_dp.c       |   4 +-
>   drivers/gpu/drm/i915/display/intel_psr.c      | 154 +++++++++---------
>   drivers/gpu/drm/i915/display/intel_psr.h      |   2 +-
>   include/drm/display/drm_dp.h                  |   2 +
>   5 files changed, 91 insertions(+), 81 deletions(-)
>
Acked-by: Masahiro Yamada <masahiro.yamada at canonical.com>