Messages in this thread | | | From | "Rafael J. Wysocki" <> | Date | Sun, 27 May 2018 12:18:05 +0200 | Subject | Re: [PATCH] PM / runtime: Drop usage count for suppliers at device link removal |
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On Thu, May 24, 2018 at 10:33 AM, Ulf Hansson <ulf.hansson@linaro.org> wrote: > In the case consumer device is runtime resumed, while the link to the > supplier is removed, the earlier call to pm_runtime_get_sync() made from > rpm_get_suppliers() does not get properly balanced with a corresponding > call to pm_runtime_put(). This leads to that suppliers remains to be > runtime resumed forever, while they don't need to. > > Let's fix the behaviour by calling rpm_put_suppliers() when dropping a > device link. Not that, since rpm_put_suppliers() checks the > link->rpm_active flag, we can correctly avoid to call pm_runtime_put() in > cases when we shouldn't. > > Reported-by: Todor Tomov <todor.tomov@linaro.org> > Fixes: 21d5c57b3726 ("PM / runtime: Use device links") > Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> > --- > > Rafael, I am not sure if this is safe from locking point of view. The device > link write lock has been taken when pm_runtime_drop_link() is called, hence I > assume calling rpm_put_suppliers() should be fine!? If not, can you please > advise how to change?
Holding the lock should be sufficient for the list to be stable, so AFAICS it is OK.
Thanks, Rafael
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