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Commit fcf712b4 authored by Ville Syrjälä's avatar Ville Syrjälä Committed by Greg Kroah-Hartman
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drm/i915: Move CSC load back into .color_commit_arm() when PSR is enabled on skl/glk

commit a8e03e00 upstream.

SKL/GLK CSC unit suffers from a nasty issue where a CSC
coeff/offset register read or write between DC5 exit and
PSR exit will undo the CSC arming performed by DMC, and
then during PSR exit the hardware will latch zeroes into
the active CSC registers. This causes any plane going
through the CSC to output all black.

We can sidestep the issue by making sure the PSR exit has
already actually happened before we touch the CSC coeff/offset
registers. Easiest way to guarantee that is to just move the
CSC programming back into the .color_commir_arm() as we force
a PSR exit (and crucially wait for it to actually happen)
prior to touching the arming registers.

When PSR (and thus also DC states) are disabled we don't
have anything to worry about, so we can keep using the
more optional _noarm() hook for writing the CSC registers.

Cc: <stable@vger.kernel.org> #v5.19+
Cc: Manasi Navare <navaremanasi@google.com>
Cc: Drew Davenport <ddavenport@chromium.org>
Cc: Imre Deak <imre.deak@intel.com>
Cc: Jouni Högander <jouni.hogander@intel.com>
Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/8283


Fixes: d13dde44 ("drm/i915: Split pipe+output CSC programming to noarm+arm pair")
Signed-off-by: default avatarVille Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320095438.17328-3-ville.syrjala@linux.intel.com


Reviewed-by: default avatarImre Deak <imre.deak@intel.com>
(cherry picked from commit 80a892a4)
Signed-off-by: default avatarJani Nikula <jani.nikula@intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 0fc6fea4
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