Re: [RFC PATCH] ARM hibernation / suspend-to-disk support code

[Frank Hofmann <frank.hofmann@tomtom.com>]

On Mon, 23 May 2011, Dave Martin wrote:

> On Mon, May 23, 2011 at 05:11:49PM +0100, Russell King - ARM Linux wrote:
[ ... ]
>> I tend to suggest that the header file is the right place, because that's
>> where the interface is defined.  Other people argue that its more likely
>> to be seen in the implementation (fiq.c).  So I'm tempted to say both,
>> but lets go with fiq.h for the time being.
>
> OK -- the {get,set}_fiq_regs patch is currently in your patch system.
>
> If you have no objection, I'll submit a patch adding the above text to apply
> on top of the other patch (or, if possible, orthogonally).
>
> ---Dave

Thanks a lot !

>
>>
>>> That argument may apply to a ton of state in the Secure World, not just
>>> the FIQ registers
>>
>> It very much does, and I know OMAP has some kind of SMC call to handle
>> this.
>

Yes, _omap_sram_idle() does that bit, it gives a physical address to the 
OMAP ROM code to save/restore the "secure state" in, triggered via smc.

Anyway, architecturally it seems to be much cleaner to _allow_ device 
drivers (or machine-specific hooks) to save/restore _more_ state than 
whatever the "core suspend code" would do, instead of _forcing_ the core 
suspend code to do everything-and-the-kitchen-sink.
That's where things like FIQ or secure state would be.

FrankH.