0eb670aac2
Since the removal of the no-semaphore boosting, we rely on timeslicing to
reorder passed inter-dependency hogs across the engines. However, we
require preemption to support timeslicing into user payloads, and not all
machine support preemption so we do not universally enable timeslicing,
even when it would correctly preempt our own inter-engine semaphores.
Since timeslicing and semaphore priority deboosting is now disabled on
Broadwell/Braswell, we have to follow suite and not use semaphores.
Testcase: igt/gem_exec_schedule/semaphore-codependency # bdw/bsw
Fixes: 18e4af04d218 ("drm/i915: Drop no-semaphore boosting")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200521140617.30015-1-chris@chris-wilson.co.uk
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.