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clocksource/drivers/arm_global_timer: Fix suspend resume

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Now the System stall is observed on TI AM437x based board (am437x-gp-evm)
during resuming from System suspend when ARM Global timer is selected as
clocksource device (CPUIdle not enabled) - SysRq are working, but nothing
else.

The reason of stall is that ARM Global timer loses its contexts during
System suspend:
   GT_CONTROL.TIMER_ENABLE = 0 (unbanked)
   GT_COUNTERx = 0

Hence, update ARM Global timer driver to reflect above behaviour
- re-enable ARM Global timer on resume (GT_CONTROL.TIMER_ENABLE = 1)
  if not enabled.

CC: Arnd Bergmann <arnd@arndb.de>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
This commit is contained in:
Grygorii Strashko 2015-11-30 20:25:12 +02:00 committed by Daniel Lezcano
parent 272a25a247
commit 9c9ae5ffee
1 changed files with 11 additions and 0 deletions
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11
drivers/clocksource/arm_global_timer.c
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@ -195,12 +195,23 @@ static cycle_t gt_clocksource_read(struct clocksource *cs)
return gt_counter_read();
}
static void gt_resume(struct clocksource *cs)
{
unsigned long ctrl;
ctrl = readl(gt_base + GT_CONTROL);
if (!(ctrl & GT_CONTROL_TIMER_ENABLE))
/* re-enable timer on resume */
writel(GT_CONTROL_TIMER_ENABLE, gt_base + GT_CONTROL);
}
static struct clocksource gt_clocksource = {
.name = "arm_global_timer",
.rating = 300,
.read = gt_clocksource_read,
.mask = CLOCKSOURCE_MASK(64),
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
.resume = gt_resume,
};
#ifdef CONFIG_CLKSRC_ARM_GLOBAL_TIMER_SCHED_CLOCK