Commit-ID: 9c9ae5ffee2831c0b8c0b002443b093e141d08f1
Gitweb: http://git.kernel.org/tip/9c9ae5ffee2831c0b8c0b002443b093e141d08f1
Author: Grygorii Strashko <grygorii.strashko@xxxxxx>
AuthorDate: Mon, 30 Nov 2015 20:25:12 +0200
Committer: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
CommitDate: Wed, 16 Dec 2015 09:58:47 +0100
clocksource/drivers/arm_global_timer: Fix suspend resume
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@xxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Felipe Balbi <balbi@xxxxxx>
Cc: Tony Lindgren <tony@xxxxxxxxxxx>
Cc: Marc Zyngier <marc.zyngier@xxxxxxx>
Reviewed-by: Santosh Shilimkar <ssantosh@xxxxxxxxxx>
Signed-off-by: Grygorii Strashko <grygorii.strashko@xxxxxx>
Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
---
drivers/clocksource/arm_global_timer.c | 11 +++++++++++
1 file changed, 11 insertions(+)
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index f99be6b..d189d8c 100644
--- a/drivers/clocksource/arm_global_timer.c
+++ b/drivers/clocksource/arm_global_timer.c
@@ -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
--
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