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authorRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-05-10 01:19:52 +0200
committerRafael J. Wysocki <rafael.j.wysocki@intel.com>2015-05-14 21:37:52 +0200
commit0d94039fabccaa81d87eafdac509d0dda4df2f7b (patch)
tree3b7697a35df7ca25b0e9d013b68a2e2702ddb465 /drivers/cpuidle
parent827a5aefc542b8fb17c00de06118e5cd0e3800f2 (diff)
cpuidle: Select a different state on tick_broadcast_enter() failures
If tick_broadcast_enter() fails in cpuidle_enter_state(), try to find another idle state to enter instead of invoking default_idle_call() immediately and returning -EBUSY which should increase the chances of saving some energy in those cases. Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Reviewed-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Tested-by: Sudeep Holla <sudeep.holla@arm.com> Acked-by: Kevin Hilman <khilman@linaro.org>
Diffstat (limited to 'drivers/cpuidle')
-rw-r--r--drivers/cpuidle/cpuidle.c20
1 files changed, 15 insertions, 5 deletions
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
index a7b9e679a2ef..af6dd599c464 100644
--- a/drivers/cpuidle/cpuidle.c
+++ b/drivers/cpuidle/cpuidle.c
@@ -73,7 +73,10 @@ int cpuidle_play_dead(void)
}
static int find_deepest_state(struct cpuidle_driver *drv,
- struct cpuidle_device *dev, bool freeze)
+ struct cpuidle_device *dev,
+ unsigned int max_latency,
+ unsigned int forbidden_flags,
+ bool freeze)
{
unsigned int latency_req = 0;
int i, ret = freeze ? -1 : CPUIDLE_DRIVER_STATE_START - 1;
@@ -83,6 +86,8 @@ static int find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_state_usage *su = &dev->states_usage[i];
if (s->disabled || su->disable || s->exit_latency <= latency_req
+ || s->exit_latency > max_latency
+ || (s->flags & forbidden_flags)
|| (freeze && !s->enter_freeze))
continue;
@@ -100,7 +105,7 @@ static int find_deepest_state(struct cpuidle_driver *drv,
int cpuidle_find_deepest_state(struct cpuidle_driver *drv,
struct cpuidle_device *dev)
{
- return find_deepest_state(drv, dev, false);
+ return find_deepest_state(drv, dev, UINT_MAX, 0, false);
}
static void enter_freeze_proper(struct cpuidle_driver *drv,
@@ -139,7 +144,7 @@ int cpuidle_enter_freeze(struct cpuidle_driver *drv, struct cpuidle_device *dev)
* that interrupts won't be enabled when it exits and allows the tick to
* be frozen safely.
*/
- index = find_deepest_state(drv, dev, true);
+ index = find_deepest_state(drv, dev, UINT_MAX, 0, true);
if (index >= 0)
enter_freeze_proper(drv, dev, index);
@@ -168,8 +173,13 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
* CPU as a broadcast timer, this call may fail if it is not available.
*/
if (broadcast && tick_broadcast_enter()) {
- default_idle_call();
- return -EBUSY;
+ index = find_deepest_state(drv, dev, target_state->exit_latency,
+ CPUIDLE_FLAG_TIMER_STOP, false);
+ if (index < 0) {
+ default_idle_call();
+ return -EBUSY;
+ }
+ target_state = &drv->states[index];
}
/* Take note of the planned idle state. */