[PATCH v2 0/1] [SRU][H] UBUNTU: SAUCE: Fix backlight control on Samsung 16727 panel

Aaron Ma aaron.ma at canonical.com
Mon Aug 2 09:14:13 UTC 2021

BugLink: https://bugs.launchpad.net/bugs/1930527

Backlight can't be controlled on 5.11- version of kernel.

The panel needs DPCD to get control of backlight on 5.11- kernel.
After 5.12 kernel introduced new Intel HDR backlight control, and it
works well on this panel.
Add quirk ID to enable DPCD on 5.11- kernel.

Because upstream kernel already got a fix, this patch is not going
to linus's tree. it's only for 5.11- stable kernel.
This patch had been submitted to stable kernel twice, and got Acked
by maintainer too. But still not applied.

It adds ID to use DPCD AUX control, it should be safe as UBUNTU SAUCE patch
for other panels.

Vendor Verified on hardware, with this quirk backlight can be changed on
5.11 kernel.

[Where problems could occur]
The panel backlight may not be changed.

Aaron Ma (1):
  UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode for Samsung 16727

 drivers/gpu/drm/drm_dp_helper.c | 1 +
 1 file changed, 1 insertion(+)


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