Re: PM: off mode

[Roger Quadros <ext-roger.quadros@nokia.com>]

Roger Quadros wrote:
> ext Roger Quadros wrote:
>> ext Kevin Hilman wrote:
>>> Roger Quadros <ext-roger.quadros@nokia.com> writes:
>>>
>>>> ext Roger Quadros wrote:
>>>>> ext Kevin Hilman wrote:
>>>>>> Roger Quadros <ext-roger.quadros@nokia.com> writes:
>>>>>>
>>>>>>> Hi Kevin,
>>>>>>>
>>>>>>>  Off mode does not seem to work on RX51 on latest PM branch. I get a
>>>>>>> reboot if I set enable_off_mode and sleep_while_idle and I wait for
>>>>>>> timeout.
>>>>>>>
>>>>>>>  Does it work on other platforms?
>>>>>>>
>>>>>> Yes, I tested on SDP, omap3evm, Beagle, Overo and RX51.
>>>>>>
>>>>>> On RX51, I'm using omap3_pm_defconfig with the debug UART changed to
>>>>>> UART3 and things work fine here.
>>>>>>
>>>>>> I using rootfs from latest fiasco image, and it drops me into an 
>>>>>> early
>>>>>> shell because /sbin/preinit fails in various ways. Note that I'm 
>>>>>> using
>>>>>> an S2.0 GP board.  Note also that I modified /sbin/preinit to launch
>>>>>> another getty on ttyS2 so I get a shell since newer kernels ignore 
>>>>>> the
>>>>>> ATAGs passed by nolo.
>>>>>>
>>>>>> Below is a console log of my boot so you can see what is going on.
>>>>>> Because /sbin/preinit enables off-mode and sleep_while_idle, I just
>>>>>> let it boot and it seems to work.
>>>>>>
>>>>>> Kevin
>>>>>>
>>>>> I am having S2.1 board and it does not work on that. It gets locked
>>>>> up and restarts after idle timeout.
>>>>> But I checked that it works on S2.0 board.
>>>>>
>>>>> Any clue what could be the problem?
>>>>>
>>>>> -roger
>>>>> -- 
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>>>>>
>>>> Kevin,
>>>>
>>>> I have some new observations.
>>>>
>>>> It works only if we load the kernel via USB. Instead, if we flash the
>>>> kernel, it will not work even with S2.0 board. It boots to shell but
>>>> after sleep timeout (5 seconds) console gets locked up and it reboots
>>>> after a while.
>>>
>>> Roger,
>>>
>>> Does this happen even with the working defconfig you sent the other day?
>>>
>>> Kevin
>>
>> The config that i sent does not work with S2.0 hardware in either case.
>> It works with S2.1 hardware only in one case i.e. kernel load via USB. 
>> It does not work if kernel is flashed.
>> Also when my config is used on S2.1, core always remains in ON mode 
>> and never hits RET/OFF mode.
>>
>> -roger
> 
> Kevin,
> 
> I just found out that it has nothing to do with kernel load via USB or 
> not. I was using an initrd while USB load which used to change vdd1 OPP, 
> that's why it was working.
> 
> So the final conclusion is, after boot to shell, if we change VDD1 OPP, 
> then off mode works fine on my S2.0 HS board.
>     e.g.
>         echo 1 > /sys/power/vdd1_opp
>         echo 1 > /sys/power/sleep_while_idle
>         echo 1 > /sys/power/enable_off_mode
> 
> It works on S2.1 board too except that garbage characters are printed on 
> console after idle timeout.
> 
> Does this give any more clue to the problem?
> 
> -roger
> 

Hi Kevin,

What compiler version do you use?

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