[PATCH v3 1/4] staging: greybus: loopback: Hold per-connection mutex across operations

Johan Hovold johan at kernel.org
Mon Nov 6 09:17:46 UTC 2017


On Mon, Nov 06, 2017 at 01:32:19AM +0000, Bryan O'Donoghue wrote:
> Commit d9fb3754ecf8 ("greybus: loopback: Relax locking during loopback
> operations") changes the holding of the per-connection mutex to be less
> restrictive because at the time of that commit per-connection mutexes were
> encapsulated by a per-driver level gb_dev.mutex.
> 
> Commit 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
> on the other hand subtracts the driver level gb_dev.mutex but neglects to
> move the mutex back to the place it was prior to commit d9fb3754ecf8
> ("greybus: loopback: Relax locking during loopback operations"), as a
> result several members of the per connection struct gb_loopback are racy.
> 
> The solution is restoring the old location of mutex_unlock(&gb->mutex) as
> it was in commit d9fb3754ecf8 ("greybus: loopback: Relax locking during
> loopback operations").
> 
> Fixes: 8e1d6c336d74 ("greybus: loopback: drop bus aggregate calculation")
> 
> Signed-off-by: Bryan O'Donoghue <pure.logic at nexus-software.ie>
> Cc: Johan Hovold <johan at kernel.org>
> Cc: Alex Elder <elder at kernel.org>
> Cc: Greg Kroah-Hartman <gregkh at linuxfoundation.org>
> Cc: Mitch Tasman <tasman at leaflabs.com>
> Cc: greybus-dev at lists.linaro.org
> Cc: devel at driverdev.osuosl.org
> Cc: linux-kernel at vger.kernel.org
> ---

This looks like it addresses both my comments on v1 (mutex and error
stats). Thanks for tracking it down.

Reviewed-by: Johan Hovold <johan at kernel.org>

Johan


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