Re: PM(?) problems on v3.3-rc1 on OMAP3

Govindraj
2012-01-20T11:21:55Z

On Fri, Jan 20, 2012 at 4:37 PM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
> On Fri, 2012-01-20 at 16:19 +0530, Govindraj wrote:
>> On Fri, Jan 20, 2012 at 4:03 PM, Tomi Valkeinen <tomi.valkeinen@ti.com> wrote:
>> > Hi,
>> >
>> > I'm testing v3.3-rc1 on OMAP3 overo, and I'm having problems probably
>> > related to PM.
>> >
>> > First, when I boot up, the console (via USB serial) is very laggy, it
>> > often takes many seconds until the key pressed appears so it's more or
>> > less unusable.
>>
>> can you try enabling CONFIG_CPU_IDLE ?
>
> Enabling CPU_IDLE does remove the problems. I don't know what it's
> supposed to do, but it seems to keep the MPU and DSS in ON state all the
> time, so the problem disappears.

3.3-rc1 has uart runtime patches merged we have removed uart dependency
for system to enter low powers states and used pm_qos calls,
but pm_qos api's seem do get activated only by enabling config_cpu_idle.

Question to kevin/Paul,

Shouldn't system be doing wfi if cpu_idle is not enabled ?

since we are mapping omap3_pm_idle to pm_idle thread
system enters low power states even if config_cpu_idle is not enabled.
Is this expected behavior?

--
Thanks,
Govindraj.R