mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-14 07:42:38 -04:00
4f45d65b78
There is a chance to meet runtime issues during configuration of CAMSS
power domains, because on the error path dev_pm_domain_detach() is
unexpectedly called with NULL or error pointer.
One of the simplest ways to reproduce the problem is to probe CAMSS
driver before registration of CAMSS power domains, for instance if
a platform CAMCC driver is simply not built.
Warning backtrace example:
Unable to handle kernel NULL pointer dereference at virtual address 00000000000001a2
<snip>
pc : dev_pm_domain_detach+0x8/0x48
lr : camss_probe+0x374/0x9c0
<snip>
Call trace:
dev_pm_domain_detach+0x8/0x48
platform_probe+0x70/0xf0
really_probe+0xc4/0x2a8
__driver_probe_device+0x80/0x140
driver_probe_device+0x48/0x170
__device_attach_driver+0xc0/0x148
bus_for_each_drv+0x88/0xf0
__device_attach+0xb0/0x1c0
device_initial_probe+0x1c/0x30
bus_probe_device+0xb4/0xc0
deferred_probe_work_func+0x90/0xd0
process_one_work+0x164/0x3e0
worker_thread+0x310/0x420
kthread+0x120/0x130
ret_from_fork+0x10/0x20
Fixes: 23aa4f0cd3 ("media: qcom: camss: Move VFE power-domain specifics into vfe.c")
Cc: <stable@vger.kernel.org>
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
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 reStructuredText 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.