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| author | Alan Stern <stern@rowland.harvard.edu> | 2011-12-06 23:24:52 +0100 |
|---|---|---|
| committer | Rafael J. Wysocki <rjw@sisk.pl> | 2011-12-07 22:26:56 +0100 |
| commit | fe6b91f47080eb17d21cbf2a39311877d57f6938 (patch) | |
| tree | 0c63640274b02fdb3c95546cf966896e97bb5877 | |
| parent | Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net (diff) | |
| download | linux-fe6b91f47080eb17d21cbf2a39311877d57f6938.tar.xz linux-fe6b91f47080eb17d21cbf2a39311877d57f6938.zip | |
PM / Driver core: leave runtime PM enabled during system shutdown
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 <neilb@suse.de>
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
| -rw-r--r-- | drivers/base/core.c | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/drivers/base/core.c b/drivers/base/core.c index d8b3d89db043..919daa7cd5b1 100644 --- 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"); |