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authorRafael J. Wysocki2012-12-22 16:59:01 -0600
committerRafael J. Wysocki2013-01-05 17:35:55 -0600
commit9f6d8f6ab26b42620a914d67f29822f9bba90233 (patch)
treeac243fb6970bf2b870e34e061281f7ad5446ad38 /Documentation
parentd1c3ed669a2d452cacfb48c2d171a1f364dae2ed (diff)
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PM: Move disabling/enabling runtime PM to late suspend/early resume
Currently, the PM core disables runtime PM for all devices right after executing subsystem/driver .suspend() callbacks for them and re-enables it right before executing subsystem/driver .resume() callbacks for them. This may lead to problems when there are two devices such that the .suspend() callback executed for one of them depends on runtime PM working for the other. In that case, if runtime PM has already been disabled for the second device, the first one's .suspend() won't work correctly (and analogously for resume). To make those issues go away, make the PM core disable runtime PM for devices right before executing subsystem/driver .suspend_late() callbacks for them and enable runtime PM for them right after executing subsystem/driver .resume_early() callbacks for them. This way the potential conflitcs between .suspend_late()/.resume_early() and their runtime PM counterparts are still prevented from happening, but the subtle ordering issues related to disabling/enabling runtime PM for devices during system suspend/resume are much easier to avoid. Reported-and-tested-by: Jan-Matthias Braun <jan_braun@gmx.net> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org> Reviewed-by: Kevin Hilman <khilman@deeprootsystems.com> Cc: 3.4+ <stable@vger.kernel.org>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/power/runtime_pm.txt9
1 files changed, 5 insertions, 4 deletions
diff --git a/Documentation/power/runtime_pm.txt b/Documentation/power/runtime_pm.txt
index 4abe83e1045a..03591a750f99 100644
--- a/Documentation/power/runtime_pm.txt
+++ b/Documentation/power/runtime_pm.txt
@@ -642,12 +642,13 @@ out the following operations:
642 * During system suspend it calls pm_runtime_get_noresume() and 642 * During system suspend it calls pm_runtime_get_noresume() and
643 pm_runtime_barrier() for every device right before executing the 643 pm_runtime_barrier() for every device right before executing the
644 subsystem-level .suspend() callback for it. In addition to that it calls 644 subsystem-level .suspend() callback for it. In addition to that it calls
645 pm_runtime_disable() for every device right after executing the 645 __pm_runtime_disable() with 'false' as the second argument for every device
646 subsystem-level .suspend() callback for it. 646 right before executing the subsystem-level .suspend_late() callback for it.
647 647
648 * During system resume it calls pm_runtime_enable() and pm_runtime_put_sync() 648 * During system resume it calls pm_runtime_enable() and pm_runtime_put_sync()
649 for every device right before and right after executing the subsystem-level 649 for every device right after executing the subsystem-level .resume_early()
650 .resume() callback for it, respectively. 650 callback and right after executing the subsystem-level .resume() callback
651 for it, respectively.
651 652
6527. Generic subsystem callbacks 6537. Generic subsystem callbacks
653 654