[RFC PATCH v4 2/4] ARM: omap: Remove cpuidle timekeeping and irq enable/disable
From: Jean Pihet <hidden>
Date: 2012-02-02 16:21:21
Also in:
linux-acpi
Rob, On Wed, Feb 1, 2012 at 4:00 AM, Robert Lee [off-list ref] wrote:
quoted hunk ↗ jump to hunk
Now that the core cpuidle driver keeps time and handles irq enabling, remove this functionality. ?Also, remove irq disabling as all paths to cpuidle_idle_call already call local_irq_disable. ?Also, restructure idle functions as needed by the cpuidle core driver changes. Signed-off-by: Robert Lee <redacted> --- ?arch/arm/mach-omap2/cpuidle34xx.c | ? 96 ++++++++++++++++-------------------- ?1 files changed, 43 insertions(+), 53 deletions(-)diff --git a/arch/arm/mach-omap2/cpuidle34xx.c b/arch/arm/mach-omap2/cpuidle34xx.c index 464cffd..9ecded5 100644 --- a/arch/arm/mach-omap2/cpuidle34xx.c +++ b/arch/arm/mach-omap2/cpuidle34xx.c
...
quoted hunk ↗ jump to hunk
@@ -100,23 +107,20 @@ static int omap3_enter_idle(struct cpuidle_device *dev,? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct cpuidle_driver *drv, ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?int index) ?{ - ? ? ? struct omap3_idle_statedata *cx = - ? ? ? ? ? ? ? ? ? ? ? cpuidle_get_statedata(&dev->states_usage[index]); - ? ? ? struct timespec ts_preidle, ts_postidle, ts_idle; - ? ? ? u32 mpu_state = cx->mpu_state, core_state = cx->core_state; - ? ? ? int idle_time; + ? ? ? struct omap3_idle_drvdata *dd = dev->states_usage[index].driver_data
A build error is triggered by the missing ";". ...
quoted hunk ↗ jump to hunk
@@ -147,18 +151,12 @@ static int omap3_enter_idle(struct cpuidle_device *dev,? ? ? ? ? ? ? ?pwrdm_for_each_clkdm(core_pd, _cpuidle_allow_idle); ? ? ? ?} -return_sleep_time: - ? ? ? getnstimeofday(&ts_postidle); - ? ? ? ts_idle = timespec_sub(ts_postidle, ts_preidle); - - ? ? ? local_irq_enable(); +leave: ? ? ? ?local_fiq_enable(); - ? ? ? idle_time = ts_idle.tv_nsec / NSEC_PER_USEC + ts_idle.tv_sec * \ - ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? USEC_PER_SEC; - - ? ? ? /* Update cpuidle counters */ - ? ? ? dev->last_residency = idle_time; + ? ? ? /* Restore original PER state if it was modified */ + ? ? ? if (dd->per_next_state != dd->per_saved_state) + ? ? ? ? ? ? ? pwrdm_set_next_pwrst(per_pd, dd->per_saved_state);
This code is not necessarily balanced with the PER state change in omap3_enter_idle_bm (cf. "/* Are we changing PER target state? */" here below), since in the core cpuidle code there is no guarantee that the calls to pre_enter and enter callbacks are balanced. In general I fear that splitting the code in two functions introduces a risk of programming non-coherent settings in the PRCM. ...
quoted hunk ↗ jump to hunk
@@ -255,8 +255,9 @@ static int omap3_enter_idle_bm(struct cpuidle_device *dev,? ? ? ? ? ? ? ? ? ? ? ? ? ? ? int index) ?{ ? ? ? ?int new_state_idx; - ? ? ? u32 core_next_state, per_next_state = 0, per_saved_state = 0, cam_state; - ? ? ? struct omap3_idle_statedata *cx; + ? ? ? u32 core_next_state, cam_state; + ? ? ? struct omap3_idle_drvdata *dd = dev->states_usage[index].driver_data; + ? ? ? struct omap3_idle_statedata *cx = &dd->state_data[index]; ? ? ? ?int ret;
The build throws a few warnings about unused variables: arch/arm/mach-omap2/cpuidle34xx.c: In function 'omap3_enter_idle_bm': arch/arm/mach-omap2/cpuidle34xx.c:261: warning: unused variable 'ret' arch/arm/mach-omap2/cpuidle34xx.c:257: warning: unused variable 'new_state_idx' ...
quoted hunk ↗ jump to hunk
?DEFINE_PER_CPU(struct cpuidle_device, omap3_idle_dev);@@ -337,7 +329,8 @@ static inline void _fill_cstate(struct cpuidle_driver *drv,? ? ? ?state->exit_latency ? ? = cpuidle_params_table[idx].exit_latency; ? ? ? ?state->target_residency = cpuidle_params_table[idx].target_residency; ? ? ? ?state->flags ? ? ? ? ? ?= CPUIDLE_FLAG_TIME_VALID; - ? ? ? state->enter ? ? ? ? ? ?= omap3_enter_idle_bm; + ? ? ? state->pre_enter ? ? ? ?= omap3_enter_idle_bm; + ? ? ? state->enter ? ? ? ? ? ?= omap3_enter_idle; ? ? ? ?sprintf(state->name, "C%d", idx + 1); ? ? ? ?strncpy(state->desc, descr, CPUIDLE_DESC_LEN);
...
Also the line at 373 is not needed anymore in omap3_idle_init, since
the enter callback is filled in in the _fill_cstate function:
/* C1 . MPU WFI + Core active */
_fill_cstate(drv, 0, "MPU ON + CORE ON");
(&drv->states[0])->enter = omap3_enter_idle; <==
not needed anymore
drv->safe_state_index = 0;
More testing on OMAP3 is needed. Let me come back with the results asap.
Regards,
Jean