074c88751d
commit 4e6f55120c7eccf6f9323bb681632e23cbcb3f3c upstream. On TGL/RKL the BIOS likes to use some kind of bogus DBUF layout that doesn't match what the spec recommends. With a single active pipe that is not going to be a problem, but with multiple pipes active skl_commit_modeset_enables() goes into an infinite loop since it can't figure out any order in which it can commit the pipes without causing DBUF overlaps between the planes. We'd need some kind of extra DBUF defrag stage in between to make the transition possible. But that is clearly way too complex a solution, so in the name of simplicity let's just sanitize the DBUF state by simply turning off all planes when we detect a pipe encroaching on its neighbours' DBUF slices. We only have to disable the primary planes as all other planes should have already been disabled (if they somehow were enabled) by earlier sanitization steps. And for good measure let's also sanitize in case the DBUF allocations of the pipes already seem to overlap each other. Cc: <stable@vger.kernel.org> # v5.14+ Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/4762 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20220204141818.1900-3-ville.syrjala@linux.intel.com Reviewed-by: Stanislav Lisovskiy <stanislav.lisovskiy@intel.com> (cherry picked from commit 15512021eb3975a8c2366e3883337e252bb0eee5) Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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.