Commit 0aabb4b5 authored Jul 15, 2016 by Charan Teja Reddy Committed by Gerrit - the friendly Code Review server Jul 15, 2016

coresight: fix the mutex deadlock issue in cpu hotplug path



The CPU hotplug notification path is called up by holding the
cpu_add_remove_lock and when the same is held by the
unregister_hotcpu_notifier() in the notifier path results in
deadlock.So, release and acquire the cpu_add_remove_lock before and
after unregistration of cpu notifiers.

Change-Id: I46d6b2ae98dc1eae7c55f8ac62325d25b48d463f
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>

parent c44279d0

drivers/coresight/coresight-etmv4.c

+4 −0

Original line number	Diff line number	Diff line
		@@ -3483,8 +3483,12 @@ out:
		return NOTIFY_OK;
		err1:
		if (--count == 0) {
		/* Release the cpu_add_remove_lock */
		cpu_maps_update_done();
		unregister_hotcpu_notifier(&etm_cpu_notifier);
		unregister_hotcpu_notifier(&etm_cpu_dying_notifier);
		/* Set to the original state of lock */
		cpu_maps_update_begin();
		}
		if (clk_disable[cpu]) {
		clk_disable_unprepare(etmdrvdata[cpu]->clk);