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authorGrygorii Strashko <grygorii.strashko@ti.com>2015-11-30 21:25:12 +0300
committerDaniel Lezcano <daniel.lezcano@linaro.org>2015-12-16 11:58:47 +0300
commit9c9ae5ffee2831c0b8c0b002443b093e141d08f1 (patch)
tree303b3805c05f09417d0653f8e6ecd993f97844ac /drivers/clocksource
parent272a25a247ce6d31315856721014635469500e96 (diff)
downloadlinux-9c9ae5ffee2831c0b8c0b002443b093e141d08f1.tar.xz
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@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>
Diffstat (limited to 'drivers/clocksource')
-rw-r--r--drivers/clocksource/arm_global_timer.c11
1 files changed, 11 insertions, 0 deletions
diff --git a/drivers/clocksource/arm_global_timer.c b/drivers/clocksource/arm_global_timer.c
index f99be6bafad1..d189d8cb69f7 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