5471864d27
[ Upstream commit 7cc29fcdfcc8784e97c5151c848e193800ec79ac ]
nr_rings is reset to 1, but when this function is called for a second
(and third!) time nr_rings > 1 is false, thus the else case is entered
to set up a buffer for the RPTR shadow and consequently written to
RB_RPTR_ADDR, hanging platforms without WHERE_AM_I firmware support.
Restructure the condition in such a way that shadow buffer setup only
ever happens when has_whereami is true; otherwise preemption is only
finalized when the number of ring buffers has not been reset to 1 yet.
Fixes: 8907afb476ac ("drm/msm: Allow a5xx to mark the RPTR shadow as privileged")
Signed-off-by: Marijn Suijten <marijn.suijten@somainline.org>
Tested-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Reviewed-by: Jordan Crouse <jcrouse@codeaurora.org>
Signed-off-by: Rob Clark <robdclark@chromium.org>
Signed-off-by: Sasha Levin <sashal@kernel.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.