Commit c86d06ba authored Sep 05, 2016 by Tejun Heo Committed by Rafael J. Wysocki Sep 05, 2016

PM / QoS: avoid calling cancel_delayed_work_sync() during early boot



of_clk_init() ends up calling into pm_qos_update_request() very early
during boot where irq is expected to stay disabled.
pm_qos_update_request() uses cancel_delayed_work_sync() which
correctly assumes that irq is enabled on invocation and
unconditionally disables and re-enables it.

Gate cancel_delayed_work_sync() invocation with kevented_up() to avoid
enabling irq unexpectedly during early boot.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-and-tested-by: Qiao Zhou <qiaozhou@asrmicro.com>
Link: http://lkml.kernel.org/r/d2501c4c-8e7b-bea3-1b01-000b36b5dfe9@asrmicro.com


Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent c6935931

kernel/power/qos.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -482,7 +482,16 @@ void pm_qos_update_request(struct pm_qos_request *req,
		return;
		}

		/*
		* This function may be called very early during boot, for example,
		* from of_clk_init(), where irq needs to stay disabled.
		* cancel_delayed_work_sync() assumes that irq is enabled on
		* invocation and re-enables it on return. Avoid calling it until
		* workqueue is initialized.
		*/
		if (keventd_up())
		cancel_delayed_work_sync(&req->work);

		__pm_qos_update_request(req, new_value);
		}
		EXPORT_SYMBOL_GPL(pm_qos_update_request);