Re: ARM suspend to disk?

[Peter Tseng <tsenpet09@gmail.com>]

On 05/01/2010 03:12 AM, Shilimkar, Santosh wrote:
>> -----Original Message-----
>> From: linux-omap-owner@vger.kernel.org [mailto:linux-omap-owner@vger.kernel.org] On Behalf Of Kevin
>> Hilman
>> Sent: Saturday, May 01, 2010 3:36 AM
>> To: Cliff Brake
>> Cc: Peter Tseng; linux-omap@vger.kernel.org
>> Subject: Re: ARM suspend to disk?
>>
>> Cliff Brake <cliff.brake@gmail.com> writes:
>>
>>> On Thu, Apr 29, 2010 at 1:58 PM, Kevin Hilman
>>> <khilman@deeprootsystems.com> wrote:
>>>
>>>> What do you expect to gain from suspend-to-disk + snapshot boot that
>>>> you don't already get from suspend-to-RAM using off-mode?
>>>>
>>>> On OMAP, with off-mode enabled, a suspend to RAM puts the entire OMAP
>>>> into full-chip off, and essentially reboots the ARM when waking up
>>>> from suspend (or idle) already.
>>>
>>> What does the resume process look like in off mode?  Does the resume
>>> pass through the bootloader?  If so, are the bits that detects resume
>>> from "off" available in U-boot?
>>
>> No, it does not pass through the boot loader.
>>
>> In general terms, resume from off-mode is the same to "normal" resume (from
>> retention) except that some additional state has to be restored before
>> continuing where you left off since the ARM core (as well as most the
>> OMAP itself) was turned off.
>>
> On suspend to disk topic, Raghu under Romit's guidance did a 
> prototype few months back as part of his internship using some of the earlier
> ARM work. The whole system snapshot was stored to the MMC card and one 
> can take that MMC card on another board and continue from where it was suspended.
> 
> We should have these patches somewhere.
> 

It would be interesting to see these. Are you able to find these patches
somewhere?

Peter