drm/i915: Move CSC load back into .color_commit_arm() when PSR is enabled on skl/glk
authorVille Syrjälä <ville.syrjala@linux.intel.com>
Mon, 20 Mar 2023 09:54:34 +0000 (11:54 +0200)
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Thu, 6 Apr 2023 10:10:56 +0000 (12:10 +0200)
commitfcf712b4e5d0aacbc193e71962bdaa4d4afe3335
tree48639f28099d9e3128550172f62594f22266b6d8
parent0fc6fea41c7122aa5f2088117f50144b507e13d7
drm/i915: Move CSC load back into .color_commit_arm() when PSR is enabled on skl/glk

commit a8e03e00b62073b494886dbff32f8b5338066c8b 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: d13dde449580 ("drm/i915: Split pipe+output CSC programming to noarm+arm pair")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320095438.17328-3-ville.syrjala@linux.intel.com
Reviewed-by: Imre Deak <imre.deak@intel.com>
(cherry picked from commit 80a892a4c2428b65366721599fc5fe50eaed35fd)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
drivers/gpu/drm/i915/display/intel_color.c