On Sat, Feb 4, 2012 at 11:02 AM, Colin Cross ccross@google.com wrote:
On Tue, Jan 31, 2012 at 7:00 PM, Robert Lee rob.lee@linaro.org wrote:
Make necessary changes to add implement time keepign and irq enabling
keeping
in the core cpuidle code. This will allow the remove of these functionalities from the platform cpuidle implementations.
Signed-off-by: Robert Lee rob.lee@linaro.org
drivers/cpuidle/cpuidle.c | 75 +++++++++++++++++++++++++++++++++++--------- include/linux/cpuidle.h | 26 ++++++++++----- 2 files changed, 76 insertions(+), 25 deletions(-)
diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index 59f4261..8ea0fc3 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -57,14 +57,18 @@ static int __cpuidle_register_device(struct cpuidle_device *dev); * cpuidle_idle_call - the main idle loop * * NOTE: no locks or semaphores should be used here
- NOTE: Should only be called from a local irq disabled context
* return non-zero on failure
*/ int cpuidle_idle_call(void) { struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); struct cpuidle_driver *drv = cpuidle_get_driver(); struct cpuidle_state *target_state;
- int next_state, entered_state;
- int idx, ret = 0;
- ktime_t t1, t2;
- s64 diff;
if (off) return -ENODEV; @@ -86,37 +90,76 @@ int cpuidle_idle_call(void) #endif
/* ask the governor for the next state */
- next_state = cpuidle_curr_governor->select(drv, dev);
- idx = cpuidle_curr_governor->select(drv, dev);
- target_state = &drv->states[idx];
- /*
- * Check with the device to see if it can enter this state or if another
- * state should be used.
- */
- if (target_state->pre_enter) {
- idx = target_state->
- pre_enter(dev, drv, idx);
Unnecessary line wrap and braces.
What's the point of the pre_enter call? This seems very similar to the prepare call that was removed in 3.2. Drivers can already demote
Hi Colin,
I asked Rob to re-introduce the .prepare callback (not .pre_enter).
The short version of why I requested this is so that I can experiment with modifying wake-up latency and theshold values dynamically based on PM QoS constraints. For an OMAP-specific example, I'd like to see our C-states no longer model both MPU and CORE power domains, and instead only model the MPU. Then when entering idle the PM QoS constraints against the CORE power domain's wake-up latency can be considered in the .prepare callback which will affect the C-state parameters as well as program the CORE low power target state.
.pre_enter isn't really right for the above case so I'm happy for it to be dropped, but I'll probably re-introduce something like .prepare in the future...
Regards, Mike
the target state in their enter call. The only thing you do between pre_enter and enter is trace and account for the time. Is there some long call you don't want included in the idle time? Some documentation would help, and you need to very clearly define the semantics of when post_enter gets called when pre_enter or enter return errors.
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