Re: [PATCH v2] mmc: dw_mmc: Disable SDIO interrupts while suspended to fix suspend/resume

From: Ulf Hansson
Date: Tue Jun 04 2019 - 03:35:08 EST

On Mon, 3 Jun 2019 at 20:41, Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> Ulf,
> On Tue, May 28, 2019 at 3:49 PM Doug Anderson <dianders@xxxxxxxxxxxx> wrote:
> >
> > > 1) As kind of stated above, did you consider a solution where the core
> > > simply disables the SDIO IRQ in case it isn't enabled for system
> > > wakeup? In this way all host drivers would benefit.
> >
> > I can give it a shot if you can give me a bunch of specific advice,
> > but I only have access to a few devices doing anything with SDIO and
> > they are all using Marvell or Broadcom on dw_mmc.
> >
> > In general I have no idea how SDIO wakeup (plumbed through the SD
> > controller) would work. As per below the only way I've seen it done
> > is totally out-of-band. ...and actually, I'm not sure I've actually
> > ever seen even the out of band stuff truly work on a system myself.
> > It's always been one of those "we should support wake on WiFi" but
> > never made it all the way to implementation. In any case, if there
> > are examples of people plumbing wakeup through the SD controller I'd
> > need to figure out how to not break them. Just doing a solution for
> > dw_mmc means I don't have to worry about this since dw_mmc definitely
> > doesn't support SDIO wakeup.
> >
> > Maybe one way to get a more generic solution is if you had an idea for
> > a patch that would work for many host controllers then you could post
> > it and I could test to confirm that it's happy on dw_mmc? ...similar
> > to when you switched dw_mmc away from the old kthread-based SDIO
> > stuff?

Let me have a look and see if I can post something for you to test.

> Unless you have time to help dig into all the possibilities here to
> help understand how this should behave across all the different host
> controllers / wakeup setups, maybe we could just land ${SUBJECT} patch
> for now and when there is more clarity we can revisit?

That's an option. I only fear that the revisit part never happens
(because of me personally being occupied with other things).

If I not able to come up with something within a week, then I will
queue up this as fix.

Kind regards