"ext Rajendra Nayak" <[EMAIL PROTECTED]> writes:
> Hi,
>
> The following patches define and enable all of the below mentioned C states
> for OMAP3.
> These are tested with a minimal kernel config on OMAP3430sdp as most drivers
> today don't have context save/restore in place and
> some even lack aggresive clock handling.
> These apply on top of the workaround patch set submitted by Jouni.
> ([PATCH 0/6] 34XX: PM: Workarounds to get omap3 to retention 4th.)
>
> The following is neccessay even with a minimal config to achieve OFF.
> $ echo 1 > /sys/power/sleep_while_idle
> $ echo 1 > /sys/power/clocks_off_while_idle
>
> The following C states are defined
> C0 - System executing code
> C1 - MPU WFI + Core active
> C2 - MPU CSWR + Core active
> C3 - MPU OFF + Core active
> C4 - MPU CSWR + Core CSWR
> C5 - MPU OFF + Core CSWR
> C6 - MPU OFF + Core OFF
>
> regards,
> Rajendra
One more general comment on these patches as I looked at the code
after applying them.
Most of the code in omap3_enter_idle in cpuidle34xx.c could be shared
between suspend/pm_idle/cpuidle. I would do these changes to share
this code between these three things:
1. read mpu_pd pwrst, neon_pd pwrst, core_pd pwrst values in
omap_sram_idle in pm34xx.c
2. Move all the logic from omap3_enter_idle to omap_sram_idle. Use
values read in previous step to decide wether ctx savings/restores
are needed, what should be written to neon_pd next_pwrst, wether
omap2_gpio_prepare_for/resume_after_retention is needed, wether to
disable/enable serial and gpio clocks.
Basically what is left into omap3_enter_idle is writing next pwrsts
and cpuidle related stuff, something like this:
static int omap3_enter_idle(struct cpuidle_device *dev,
struct cpuidle_state *state)
{
struct omap3_processor_cx *cx = cpuidle_get_statedata(state);
struct timespec ts_preidle, ts_postidle, ts_idle;
struct powerdomain *mpu_pd, *core_pd;
current_cx_state = *cx;
if (cx->type == OMAP3_STATE_C0) {
/* Do nothing for C0, not even a wfi */
return 0;
}
local_irq_disable();
local_fiq_disable();
/* Used to keep track of the total time in idle */
getnstimeofday(&ts_preidle);
if (cx->type > OMAP3_STATE_C1)
sched_clock_idle_sleep_event(); /* about to enter deep idle */
mpu_pd = pwrdm_lookup("mpu_pwrdm");
core_pd = pwrdm_lookup("core_pwrdm");
pwrdm_set_next_pwrst(mpu_pd, cx->mpu_state);
pwrdm_set_next_pwrst(core_pd, cx->core_state);
if (omap_irq_pending())
goto return_sleep_time;
/* Execute ARM wfi */
omap_sram_idle();
return_sleep_time:
getnstimeofday(&ts_postidle);
ts_idle = timespec_sub(ts_postidle, ts_preidle);
if (cx->type > OMAP3_STATE_C1)
sched_clock_idle_wakeup_event(timespec_to_ns(&ts_idle));
local_irq_enable();
local_fiq_disable();
return (u32)timespec_to_ns(&ts_idle)/1000;
}
If this is not done, we need to copy paste code from omap3_enter_idle
into suspend code anyway if we want to use offmode in it. It would be
more nice to have one funcion with this logic shared between
suspend/pm_idle/cpuidle rather than two or even three copies of it.
--
Jouni Högander
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