625af47255
Commit 3db9d590557d ("drm/i915/gt: Reset twice") modified the code to
always hit the GDRST register twice when doing a reset, with the
reported aim to fix invalid post-reset engine state on some platforms
(Jasperlake being the only one actually mentioned).
This is a problem on MTL, due to the fact that we have to apply a time
consuming WA (coming in the next patch) every time we hit the GDRST
register in a way that can include the GSC engine. Even post MTL, the
expectation is that we'll have some work to do before and after hitting
the GDRST if the GSC is involved.
Since the issue requiring the double reset seems to be limited to older
platforms, instead of trying to handle the double-reset on MTL and
future platforms it is just easier to turn it off. The default on MTL is
also for GuC to own engine reset, with i915 only covering full-GT reset.
Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Andi Shyti <andi.shyti@linux.intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Gwan-gyeong Mun <gwan-gyeong.mun@intel.com>
Cc: John Harrison <John.C.Harrison@Intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230323231857.2194435-1-daniele.ceraolospurio@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.