[PATCH 0/4][SRU][Unstable] Intel Gen 9 brightness cannot be controlled

[AceLan Kao]

BugLink: https://bugs.launchpad.net/bugs/1861521

[Impact]
After Ubuntu-5.4.0-9.12 which introduce DPCD backlight patches, the
backlight control on some platforms fail to work.
It seems using OUI string to map the panels which support DPCD
backlight doesn't work well, it mis-mapped those panel that doesn't
support DPCD backlight, and breaks the backlight control.

[Fix]
The author of the origin DPCD backlight patches recently provides a
DP quirks based on EDID identification.

[Fix]
Verified on the machine with DPCD backlight and also on the machine
which has regression with the OUI quirks, both of them work now.

[Regression Potential]
Low, it introduce a new quirks to list the panels which support DPCD
backlight.

Lyude Paul (4):
  UBUNTU: SAUCE: drm/i915: Fix eDP DPCD aux max backlight calculations
  UBUNTU: SAUCE: drm/dp: Introduce EDID-based quirks
  UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode on X1 Extreme 2nd
    Gen 4K AMOLED panel
  UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode for some Dell CML
    2020 panels

 drivers/gpu/drm/drm_dp_helper.c               |  79 +++++++++
 drivers/gpu/drm/drm_dp_mst_topology.c         |   3 +-
 .../drm/i915/display/intel_display_types.h    |   4 +
 drivers/gpu/drm/i915/display/intel_dp.c       |  11 +-
 .../drm/i915/display/intel_dp_aux_backlight.c | 164 ++++++++++++------
 drivers/gpu/drm/i915/display/intel_dp_mst.c   |   2 +-
 drivers/gpu/drm/i915/display/intel_psr.c      |   2 +-
 include/drm/drm_dp_helper.h                   |  21 ++-
 8 files changed, 225 insertions(+), 61 deletions(-)

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2.17.1