4e29fb89f7
commit dc3421560a67361442f33ec962fc6dd48895a0df upstream.
When considering whether to mark one context as stopped and another as
started we need to look at whether the previous and new _contexts_ are
different and not just requests. Otherwise the software tracked context
start time was incorrectly updated to the most recent lite-restore time-
stamp, which was in some cases resulting in active time going backward,
until the context switch (typically the heartbeat pulse) would synchronise
with the hardware tracked context runtime. Easiest use case to observe
this behaviour was with a full screen clients with close to 100% engine
load.
Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: bb6287cb1886 ("drm/i915: Track context current active time")
Cc: <stable@vger.kernel.org> # v5.19+
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230320151423.1708436-1-tvrtko.ursulin@linux.intel.com
[tursulin: Fix spelling in commit msg.]
(cherry picked from commit b3e70051879c665acdd3a1ab50d0ed58d6a8001f)
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.