b3f74938d6
All timestamps returned by GuC for GuC PMU busyness are captured from
GUC PM TIMESTAMP. Since this timestamp does not tick when GuC goes idle,
kmd uses RING_TIMESTAMP to measure busyness of an engine with an active
context. In further stress testing, the MMIO read of the RING_TIMESTAMP
is seen to cause a rare hang. Resolve the issue by using gt specific
timestamp from PM which is in sync with the GuC PM timestamp.
Fixes: 77cdd054dd2c ("drm/i915/pmu: Connect engine busyness stats from GuC to pmu")
Signed-off-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@intel.com>
Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>
Signed-off-by: John Harrison <John.C.Harrison@Intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220111015523.225562-1-umesh.nerlige.ramappa@intel.com
(cherry picked from commit 721fd84ea1fe957453587efad5fdc44dfba58e04)
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@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.