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8532fd078d
[ Upstream commit b44b9bc7cab2967c3d6a791b1cd542c89fc07f0e ]
If a driver calls dev_pm_opp_find_bw_ceil/floor() the retrieve bandwidth
from the OPP table but the bandwidth table was not created because the
interconnect properties were missing in the OPP consumer node, the
kernel will crash with:
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000004
...
pc : _read_bw+0x8/0x10
lr : _opp_table_find_key+0x9c/0x174
...
Call trace:
_read_bw+0x8/0x10 (P)
_opp_table_find_key+0x9c/0x174 (L)
_find_key+0x98/0x168
dev_pm_opp_find_bw_ceil+0x50/0x88
...
In order to fix the crash, create an assert function to check
if the bandwidth table was created before trying to get a
bandwidth with _read_bw().
Fixes: add1dc094a ("OPP: Use generic key finding helpers for bandwidth key")
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.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.