After commit aa7a9275ab ("PM: sleep: Suspend async parents after
suspending children"), the following scenario is possible:
1. Device A is async and it depends on device B that is sync.
2. Async suspend is scheduled for A before the processing of B is
started.
3. A is waiting for B.
4. In the meantime, an unrelated device fails to suspend and returns
an error.
5. The processing of B doesn't start at all and its power.completion is
not updated.
6. A is still waiting for B when async_synchronize_full() is called.
7. Deadlock ensues.
To prevent this from happening, update power.completion for all devices
on errors in all suspend phases, but do not do it directly for devices
that are already being processed or are waiting for the processing to
start because in those cases it may be necessary to wait for the
processing to actually complete before updating power.completion for
the device.
Fixes: aa7a9275ab ("PM: sleep: Suspend async parents after suspending children")
Fixes: 443046d1ad ("PM: sleep: Make suspend of devices more asynchronous")
Closes: https://lore.kernel.org/linux-pm/e13740a0-88f3-4a6f-920f-15805071a7d6@linaro.org/
Reported-and-tested-by: Tudor Ambarus <tudor.ambarus@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Link: https://patch.msgid.link/6191258.lOV4Wx5bFT@rjwysocki.net
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