mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
synced 2026-09-22 09:34:56 +02:00
Stephan Gerhold
efb8a170a3
There is no devfreq on a3xx at the moment since gpu_busy is not
implemented. This means that msm_devfreq_init() will return early
and the entire devfreq setup is skipped.
However, msm_devfreq_active() and msm_devfreq_idle() are still called
unconditionally later, causing a NULL pointer dereference:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000010
Internal error: Oops: 96000004 [#1] PREEMPT SMP
CPU: 0 PID: 133 Comm: ring0 Not tainted 5.15.0-rc1 #4
Hardware name: Longcheer L8150 (DT)
pc : mutex_lock_io+0x2bc/0x2f0
lr : msm_devfreq_active+0x3c/0xe0 [msm]
Call trace:
mutex_lock_io+0x2bc/0x2f0
msm_gpu_submit+0x164/0x180 [msm]
msm_job_run+0x54/0xe0 [msm]
drm_sched_main+0x2b0/0x4a0 [gpu_sched]
kthread+0x154/0x160
ret_from_fork+0x10/0x20
Fix this by adding a check in msm_devfreq_active/idle() which ensures
that devfreq was actually initialized earlier.
Fixes: 9bc9557017 ("drm/msm: Devfreq tuning")
Reported-by: Nikita Travkin <nikita@trvn.ru>
Tested-by: Nikita Travkin <nikita@trvn.ru>
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
Link: https://lore.kernel.org/r/20210913164556.16284-1-stephan@gerhold.net
Signed-off-by: Rob Clark <robdclark@chromium.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.