]> git.proxmox.com Git - mirror_ubuntu-artful-kernel.git/commit
PM / Clocks: Do not acquire a mutex under a spinlock
authorRafael J. Wysocki <rjw@sisk.pl>
Mon, 26 Sep 2011 17:40:23 +0000 (19:40 +0200)
committerRafael J. Wysocki <rjw@sisk.pl>
Mon, 26 Sep 2011 17:40:23 +0000 (19:40 +0200)
commite8b364b88cc4001b21c28c1ecf1e1e3ffbe162e6
tree980f84081c2278ff2b6bb4a113d949a1730759a8
parentf9d81f61c84aca693bc353dfef4b8c36c2e5e1b5
PM / Clocks: Do not acquire a mutex under a spinlock

Commit b7ab83e (PM: Use spinlock instead of mutex in clock
management functions) introduced a regression causing clocks_mutex
to be acquired under a spinlock.  This happens because
pm_clk_suspend() and pm_clk_resume() call pm_clk_acquire() under
pcd->lock, but pm_clk_acquire() executes clk_get() which causes
clocks_mutex to be acquired.  Similarly, __pm_clk_remove(),
executed under pcd->lock, calls clk_put(), which also causes
clocks_mutex to be acquired.

To fix those problems make pm_clk_add() call pm_clk_acquire(), so
that pm_clk_suspend() and pm_clk_resume() don't have to do that.
Change pm_clk_remove() and pm_clk_destroy() to separate
modifications of the pcd->clock_list list from the actual removal of
PM clock entry objects done by __pm_clk_remove().

Reported-and-tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
drivers/base/power/clock_ops.c