summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel
diff options
context:
space:
mode:
authorLorenzo Pieralisi <Lorenzo.Pieralisi@arm.com>2012-07-06 11:06:49 +0100
committerRussell King <rmk+kernel@arm.linux.org.uk>2012-07-09 17:41:09 +0100
commit27a5569dc66ecce06cb532542ddcd0b6da8783f6 (patch)
tree750cb3584ca6e85ec284db746ecb724786e7637a /arch/arm/kernel
parenta5203c4ce6750730b1d95a8bc1e8214765450f7e (diff)
ARM: 7444/1: kernel: add arch-timer C3STOP feature
When a CPU is shutdown its architected timer comparators registers are lost. Within CPU idle, before processors enter shutdown they enter clock events broadcast mode through the clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, cpuid); function where the local timers are emulated by a global always-on timer. On CPU resume, the per-CPU tick device normal mode is restored by exiting broadcast mode through clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, cpuid); In order for this mechanism to function, architected timers should add to their feature C3STOP, which means that they are not able to function when the CPU is in off-mode. Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Diffstat (limited to 'arch/arm/kernel')
-rw-r--r--arch/arm/kernel/arch_timer.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/arm/kernel/arch_timer.c b/arch/arm/kernel/arch_timer.c
index dd58035621f..df44c8cf9e2 100644
--- a/arch/arm/kernel/arch_timer.c
+++ b/arch/arm/kernel/arch_timer.c
@@ -137,7 +137,7 @@ static int __cpuinit arch_timer_setup(struct clock_event_device *clk)
/* Be safe... */
arch_timer_disable();
- clk->features = CLOCK_EVT_FEAT_ONESHOT;
+ clk->features = CLOCK_EVT_FEAT_ONESHOT | CLOCK_EVT_FEAT_C3STOP;
clk->name = "arch_sys_timer";
clk->rating = 450;
clk->set_mode = arch_timer_set_mode;