ff50716b7d
[ Upstream commit fbec4e7fed89b579f2483041fabf9650fb0dd6bc ]
smp_call_function always runs its callback in hard IRQ context, even on
PREEMPT_RT, where spinlocks can sleep. So we need to use a raw spinlock
for cgr_lock to ensure we aren't waiting on a sleeping task.
Although this bug has existed for a while, it was not apparent until
commit ef2a8d5478b9 ("net: dpaa: Adjust queue depth on rate change")
which invokes smp_call_function_single via qman_update_cgr_safe every
time a link goes up or down.
Fixes: 96f413f47677 ("soc/fsl/qbman: fix issue in qman_delete_cgr_safe()")
CC: stable@vger.kernel.org
Reported-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Closes: https://lore.kernel.org/all/20230323153935.nofnjucqjqnz34ej@skbuf/
Reported-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Closes: https://lore.kernel.org/linux-arm-kernel/87wmsyvclu.fsf@pengutronix.de/
Signed-off-by: Sean Anderson <sean.anderson@linux.dev>
Reviewed-by: Camelia Groza <camelia.groza@nxp.com>
Tested-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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.