Commit 2e798855 authored Jul 19, 2016 by Charan Teja Reddy Committed by Gerrit - the friendly Code Review server Jul 19, 2016

coresight: fix the mutex deadlock issue in cpu hotplug notify 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,remove the unregister_hotcpu_notifier() from the notification path as
also the presence of qdss etm notifier doesn't cause any overhead.

Change-Id: I97f150fa053e4e5f58c8cad7cdf2d8ae97a3f774
Signed-off-by: Charan Teja Reddy <charante@codeaurora.org>

parent 323ea2db

drivers/coresight/coresight-etmv4.c

+0 −8

Original line number	Diff line number	Diff line
		@@ -3482,14 +3482,6 @@ static int etm_cpu_callback(struct notifier_block *nfb, unsigned long action,
		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);
		clk_disable[cpu] = false;