[PATCH v3 1/1] misc: sram: add dev_pm_ops to support module power gate

[Shenwei Wang]

> -----Original Message-----
> From: Sudeep Holla [mailto:sudeep.holla at arm.com]
> Sent: 2015年8月25日 9:41
> To: Wang Shenwei-B38339
> Cc: Sudeep Holla; gregkh at linuxfoundation.org; arnd at arndb.de; Huang
> Yongcai-B20788; linux-arm-kernel at lists.infradead.org
> Subject: Re: [PATCH v3 1/1] misc: sram: add dev_pm_ops to support module
> power gate
> >> What I meant is who will be using the SRAM when entering S2R that you
> >> need to save the content. Either the user needs to take care of the
> >> content or just release the pool when not in use. When the sram pool has no
> user, clock can be gated.
> >>
> >> Again can you give details of this use-case.
> >
> > We are not talking about clock gate state. Here we are handling the
> > power gate for this SRAM IP block. Of course, you can ask each driver
> > to save its contents during low power state, but I think the easier
> > way is to save the contents in this sram driver and just leave the drivers who
> use this sram behave as is today.
> >
> 
> I don't like that solution as it's not scalable with SRAM size and saving all the
> content of SRAM just because of few active regions makes no sense to me
> at-least. I prefer leaving it to the users to handle that rather than SRAM driver.

I don't think it is not scalable. The choice should be made by the application.
From the driver side, it should be able to provide the way to retain its contents
during power gate. 

Regards,
Shenwei

> Regards,
> Sudeep