clockevents: Fix generic broadcast for FEAT_C3STOP (5d1d9a29) · Commits · 戴 / test

Commit : "clockevents: Add generic timer broadcast function" made tick_device_uses_broadcast set up the generic broadcast function for dummy devices (where !tick_device_is_functional(dev)), but neglected to set up the broadcast function for devices that stop in low power states (with the CLOCK_EVT_FEAT_C3STOP flag). When these devices enter low power states they will not have the generic broadcast function assigned, and will bring down the system when an attempt is made to broadcast to them. This patch ensures that the broadcast function is also assigned for devices which require broadcast in low power states. Reported-by:

Stephen Warren <swarren@nvidia.com> Signed-off-by:

Mark Rutland <mark.rutland@arm.com> Tested-by:

Stephen Warren <swarren@nvidia.com> Cc: linux-arm-kernel@lists.infradead.org Cc: nico@linaro.org Cc: Marc.Zyngier@arm.com Cc: Will.Deacon@arm.com Cc: santosh.shilimkar@ti.com Cc: john.stultz@linaro.org Signed-off-by:

Thomas Gleixner <tglx@linutronix.de>

kernel/time/tick-broadcast.c

+14 −8

Original line number	Diff line number	Diff line
		@@ -92,6 +92,17 @@ static void err_broadcast(const struct cpumask *mask)
		pr_crit_once("Failed to broadcast timer tick. Some CPUs may be unresponsive.\n");
		}

		static void tick_device_setup_broadcast_func(struct clock_event_device *dev)
		{
		if (!dev->broadcast)
		dev->broadcast = tick_broadcast;
		if (!dev->broadcast) {
		pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
		dev->name);
		dev->broadcast = err_broadcast;
		}
		}

		/*
		* Check, if the device is disfunctional and a place holder, which
		* needs to be handled by the broadcast device.
		@@ -111,13 +122,7 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
		*/
		if (!tick_device_is_functional(dev)) {
		dev->event_handler = tick_handle_periodic;
		if (!dev->broadcast)
		dev->broadcast = tick_broadcast;
		if (!dev->broadcast) {
		pr_warn_once("%s depends on broadcast, but no broadcast function available\n",
		dev->name);
		dev->broadcast = err_broadcast;
		}
		tick_device_setup_broadcast_func(dev);
		cpumask_set_cpu(cpu, tick_get_broadcast_mask());
		tick_broadcast_start_periodic(tick_broadcast_device.evtdev);
		ret = 1;
		@@ -129,9 +134,10 @@ int tick_device_uses_broadcast(struct clock_event_device *dev, int cpu)
		*/
		if (!(dev->features & CLOCK_EVT_FEAT_C3STOP)) {
		int cpu = smp_processor_id();

		cpumask_clear_cpu(cpu, tick_get_broadcast_mask());
		tick_broadcast_clear_oneshot(cpu);
		} else {
		tick_device_setup_broadcast_func(dev);
		}
		}
		raw_spin_unlock_irqrestore(&tick_broadcast_lock, flags);

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