Re: PM: off mode

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

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

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