On Sat, Feb 05, 2022 at 05:38:56AM +0100, Mario Kleiner wrote:

Upstream commit id in Linux 5.17-rc: 99510e1afb4863a225207146bd988064c5fd0629 ("drm/i915: Disable DSB usage for now").

I'd like to nominate that patch for application to the 5.15-stable tree. It applies trivially after dropping the ...

.has_pxp = 1, \

... line of context. That line of context was introduced by the unrelated feature introduced later by 6f8e203897144e59de00ed910982af3d7c3e4a7f ("drm/i915/pxp: enable PXP for integrated Gen12"), so can be safely dropped.

Disabling use of the DSB for GAMMA_LUT updates should fix corrupted display colors on Intel Tigerlake, Rocketlake, DG-1 and Alderlake-S Generation 12 graphics. Good explanation is in the upstream commit, but for reference here the bug report which led to the bug diagnosis and fix:

https://gitlab.freedesktop.org/drm/intel/-/issues/3916

This would make high color precision and HDR display modes usable on Gen 12 graphics with Linux 5.51-stable.

Now queued up (also for 5.16.y)

thanks,

greg k-h