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| author | Stephen Boyd <sboyd@codeaurora.org> | 2013-04-17 16:26:18 -0700 |
|---|---|---|
| committer | Olof Johansson <olof@lixom.net> | 2013-04-26 17:17:29 -0700 |
| commit | f31c2f1c68aff83277eddc6798adf3438e9c680a (patch) | |
| tree | 2019d040fe052e6979ebd211f12ec377da5f5c1e /drivers/clocksource | |
| parent | 405f5e5ee53339cf5d5d1753f8614938b1222562 (diff) | |
| download | linux-f31c2f1c68aff83277eddc6798adf3438e9c680a.tar.bz2 | |
ARM: arch_timer: Silence debug preempt warnings
Hot-plugging with CONFIG_DEBUG_PREEMPT=y on a device with arm
architected timers causes a slew of "using smp_processor_id() in
preemptible" warnings:
BUG: using smp_processor_id() in preemptible [00000000] code: sh/111
caller is arch_timer_cpu_notify+0x14/0xc8
This happens because sometimes the cpu notifier,
arch_timer_cpu_notify(), is called in preemptible context and
other times in non-preemptible context but we use this_cpu_ptr()
to retrieve the clockevent in all cases. We're only going to
actually use the pointer in non-preemptible context though, so
push the this_cpu_ptr() access down into the cases to force the
checks to occur only in non-preemptible contexts.
Cc: John Stultz <john.stultz@linaro.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Marc Zyngier <Marc.Zyngier@arm.com>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Olof Johansson <olof@lixom.net>
Diffstat (limited to 'drivers/clocksource')
| -rw-r--r-- | drivers/clocksource/arm_arch_timer.c | 10 |
1 files changed, 6 insertions, 4 deletions
diff --git a/drivers/clocksource/arm_arch_timer.c b/drivers/clocksource/arm_arch_timer.c index 122ff05628b5..a2b254189782 100644 --- a/drivers/clocksource/arm_arch_timer.c +++ b/drivers/clocksource/arm_arch_timer.c @@ -248,14 +248,16 @@ static void __cpuinit arch_timer_stop(struct clock_event_device *clk) static int __cpuinit arch_timer_cpu_notify(struct notifier_block *self, unsigned long action, void *hcpu) { - struct clock_event_device *evt = this_cpu_ptr(arch_timer_evt); - + /* + * Grab cpu pointer in each case to avoid spurious + * preemptible warnings + */ switch (action & ~CPU_TASKS_FROZEN) { case CPU_STARTING: - arch_timer_setup(evt); + arch_timer_setup(this_cpu_ptr(arch_timer_evt)); break; case CPU_DYING: - arch_timer_stop(evt); + arch_timer_stop(this_cpu_ptr(arch_timer_evt)); break; } |