982b1d002f
We cannot let the request be retired and freed while we are trying to dump it during error capture. It is not sufficient just to grab a reference to the request, as during retirement we may free the ring which we are also dumping. So take the engine lock to prevent retiring and freeing of the request. Reported-by: Alex Shumsky <alexthreed@gmail.com> Fixes:83c317832e("drm/i915: Dump the ringbuffer of the active request for debugging") Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com> Cc: Alex Shumsky <alexthreed@gmail.com> Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190715080946.15593-6-chris@chris-wilson.co.uk (cherry picked from commitcfe7288c27) 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.