a8e03e00b6
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>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.