Re: [EXTERNAL] Re: wlcore getting stuck on hikey after the runtime PM autosuspend support change

[Tony Lindgren <tony@atomide.com>]

* Ricardo Salveti <rsalveti@rsalveti.net> [181215 03:38]:
> On Fri, Dec 14, 2018 at 9:29 PM Tony Lindgren <tony@atomide.com> wrote:
> > * Ricardo Salveti <rsalveti@rsalveti.net> [181214 12:42]:
> > > Basically since commit 60f36637bbbd ("wlcore: sdio: allow pm to handle
> > > sdio power") PM is now handling the sdio power off/on process, and if
> > > wl12xx_sdio_power_on gets called right after wl12xx_sdio_power_off (if
> > > down/up), the device will not go to the required power off/on sequence
> > > (since PM will abort the suspend process), and the firmware loading
> > > process will fail. I would guess the problem only happens with
> > > autosuspend because of the extra delay it causes (pm_runtime_put
> > > always returns -EBUSY on wl12xx_sdio_power_off with autosuspend).
> >
> > OK thanks for the update, that's interesting.
> >
> > > Is there a way to force the suspend on wl12xx_sdio_power_off, or
> > > should we partially restore the old behavior?
> >
> > Well usually we could do pm_runtime_put_sync_suspend() but
> > here it won't help as the pm_runtime_put() is already in
> > progress by the SDIO subsystem and that's why we get -EBUSY.
> >
> > Does adding a little wait at the end of wl12xx_sdio_power_off()
> > before return? Maybe something like:
> >
> >         /* Make sure the card gets powered off */
> >         while (error == -EBUSY && !pm_runtime_suspended(&card->dev) &&
> >                 retries--) {
> >                 msleep(100);
> >         }
> 
> Yes, this is enough to force the power off process and fixes the hang
> I was having.

OK

> Also tried playing a bit with the msleep value and can confirm it
> usually needs to wait between 30-40 milliseconds before powering the
> card off.

OK thanks for checking that, I was wondering about that too.

> Do you mind sending a patch with the above changes then? I can help
> testing with the boards I have.

Yes I'll send a patch today.

Regards,

Tony