From fe6b91f47080eb17d21cbf2a39311877d57f6938 Mon Sep 17 00:00:00 2001 From: Alan Stern Date: Tue, 6 Dec 2011 23:24:52 +0100 Subject: [PATCH] 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 Signed-off-by: Alan Stern Acked-by: Greg Kroah-Hartman Signed-off-by: Rafael J. Wysocki --- drivers/base/core.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/base/core.c b/drivers/base/core.c index d8b3d89db04..919daa7cd5b 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"); -- 2.41.0