[SRU] [H/Unstable/OEM-5.10] [PATCH 0/1] Fix screen flickering when two 4K 60Hz monitors are connected to AMD Oland GFX

[Kai-Heng Feng]

BugLink: https://bugs.launchpad.net/bugs/1928361

[Impact]
Screen flickers rapidly when two 4K 60Hz monitors are connected to AMD
Oland GFX.

[Fix]
Disable certain power saving feature to keep the performance to output
two 4K 60Hz monitors.

[Test]
Plug two 4K 60Hz and stare at the monitors.
With the patch applied, no more flickers on the screen.

[Where problems could occur]
The GFX clock was restrained for stability on laptops. So if those
laptops have ability to output to dual 4K 60Hz monitors, the systems can
become unstable.

However, Oland is really old chip, those laptops neither have 4K
LVDS, nor have 4K capable HDMI/DP output.

Kai-Heng Feng (1):
  drm/radeon/dpm: Disable sclk switching on Oland when two 4K 60Hz
    monitors are connected

 drivers/gpu/drm/radeon/radeon.h    | 1 +
 drivers/gpu/drm/radeon/radeon_pm.c | 8 ++++++++
 drivers/gpu/drm/radeon/si_dpm.c    | 3 +++
 3 files changed, 12 insertions(+)

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2.30.2