bef1f14881
commit 5feba0e905c495a217aea9db4ea91093d8fe5dde upstream. We don't have a persistent fb holding a reference to the frontbuffer object, so every time we do the get+put we throw the frontbuffer object immediately away. And so the next time around we get a pristine frontbuffer object with bits==0 even for the old vma. This confuses the frontbuffer tracking code which understandably expects the old frontbuffer to have the overlay's bit set. Fix this by hanging on to the frontbuffer reference until the next flip. And just to make this a bit more clear let's track the frontbuffer explicitly instead of just grabbing it via the old vma. Cc: stable@vger.kernel.org Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Closes: https://gitlab.freedesktop.org/drm/intel/-/issues/1136 Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20210209021918.16234-2-ville.syrjala@linux.intel.com Fixes: 8e7cb1799b4f ("drm/i915: Extract intel_frontbuffer active tracking") Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk> (cherry picked from commit 553c23bdb4775130f333f07a51b047276bc53f79) Signed-off-by: Jani Nikula <jani.nikula@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.