On 28/04/2022 05:11, Suzuki K Poulose wrote:

Hi Guilherme,

On 27/04/2022 23:49, Guilherme G. Piccoli wrote:

quoted

The panic notifier infrastructure executes registered callbacks when
a panic event happens - such callbacks are executed in atomic context,
with interrupts and preemption disabled in the running CPU and all other
CPUs disabled. That said, mutexes in such context are not a good idea.

This patch replaces a regular mutex with a mutex_trylock safer approach;
given the nature of the mutex used in the driver, it should be pretty
uncommon being unable to acquire such mutex in the panic path, hence
no functional change should be observed (and if it is, that would be
likely a deadlock with the regular mutex).

Fixes: 2227b7c74634 ("coresight: add support for CPU debug module")
Cc: Leo Yan <redacted>
Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Mike Leach <redacted>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Guilherme G. Piccoli <gpiccoli@igalia.com>

How would you like to proceed with queuing this ? I am happy
either way. In case you plan to push this as part of this
series (I don't see any potential conflicts) :

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>

Hi Suzuki, some other maintainers are taking the patches to their next
branches for example. I'm working on V2, and I guess in the end would be
nice to reduce the size of the series a bit.

So, do you think you could pick this one for your coresight/next branch
(or even for rc cycle, your call - this is really a fix)?
This way, I won't re-submit this one in V2, since it's gonna be merged
already in your branch.

Thanks in advance,


Guilherme