From 9214eeaed2f65ed7a9846174f7530a686ab5dd45 Mon Sep 17 00:00:00 2001 From: Mark Rutland Date: Fri, 8 Feb 2013 15:24:07 +0000 Subject: [PATCH] clockevents: Fix generic broadcast for FEAT_C3STOP Commit 29f0da8d0f: "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 Signed-off-by: Mark Rutland Tested-by: Stephen Warren 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 --- kernel/time/tick-broadcast.c | 22 ++++++++++++++-------- 1 file changed, 14 insertions(+), 8 deletions(-) diff --git a/kernel/time/tick-broadcast.c b/kernel/time/tick-broadcast.c index f726537d24ebd..2fb8cb88df8d0 100644 --- a/kernel/time/tick-broadcast.c +++ b/kernel/time/tick-broadcast.c @@ -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); -- 2.39.5