This is a note to let you know that I've just added the patch titled
PM / Driver core: leave runtime PM enabled during system shutdown
to the 3.0-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
pm-driver-core-leave-runtime-pm-enabled-during-system-shutdown.patch
and it can be found in the queue-3.0 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From fe6b91f47080eb17d21cbf2a39311877d57f6938 Mon Sep 17 00:00:00 2001
From: Alan Stern <[email protected]>
Date: Tue, 6 Dec 2011 23:24:52 +0100
Subject: PM / Driver core: leave runtime PM enabled during system shutdown
From: Alan Stern <[email protected]>
commit fe6b91f47080eb17d21cbf2a39311877d57f6938 upstream.
Disabling all runtime PM during system shutdown turns out not to be a
good idea, because some devices may need to be woken up from a
low-power state at that time.
The whole point of disabling runtime PM for system shutdown was to
prevent untimely runtime-suspend method calls. This patch (as1504)
accomplishes the same result by incrementing the usage count for each
device and waiting for ongoing runtime-PM callbacks to finish. This
is what we already do during system suspend and hibernation, which
makes sense since the shutdown method is pretty much a legacy analog
of the pm->poweroff method.
This fixes a recent regression on some OMAP systems introduced by
commit af8db1508f2c9f3b6e633e2d2d906c6557c617f9 (PM / driver core:
disable device's runtime PM during shutdown).
Reported-and-tested-by: NeilBrown <[email protected]>
Signed-off-by: Alan Stern <[email protected]>
Acked-by: Greg Kroah-Hartman <[email protected]>
Signed-off-by: Rafael J. Wysocki <[email protected]>
Cc: Kostyantyn Shlyakhovoy <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/base/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)
--- a/drivers/base/core.c
+++ b/drivers/base/core.c
@@ -1743,8 +1743,10 @@ void device_shutdown(void)
*/
list_del_init(&dev->kobj.entry);
spin_unlock(&devices_kset->list_lock);
- /* Disable all device's runtime power management */
- pm_runtime_disable(dev);
+
+ /* Don't allow any more runtime suspends */
+ pm_runtime_get_noresume(dev);
+ pm_runtime_barrier(dev);
if (dev->bus && dev->bus->shutdown) {
dev_dbg(dev, "shutdown\n");
Patches currently in stable-queue which might be from [email protected]
are
queue-3.0/pm-driver-core-leave-runtime-pm-enabled-during-system-shutdown.patch
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