Re: [PATCH 2/2] input: touch: eeti: read hardware state once after wakeup

[Dmitry Torokhov <dmitry.torokhov@gmail.com>]

On Sun, Apr 28, 2019 at 09:18:46AM +0200, Daniel Mack wrote:
> On 23/4/2019 10:41 AM, Dmitry Torokhov wrote:
> > On Tue, Apr 23, 2019 at 06:51:32AM +0200, Daniel Mack wrote:
> >> Hi Dmitry,
> >>
> >> On 23/4/2019 5:17 AM, Dmitry Torokhov wrote:
> >>> On Mon, Apr 22, 2019 at 10:35:40AM +0200, Daniel Mack wrote:
> >>>> For systems in which the touch IRQ is acting as wakeup source, the interrupt
> >>>> controller might not latch the GPIO IRQ during sleep. In such cases, the
> >>>> interrupt will never occur again after resume, hence the touch screen
> >>>> appears dead.
> >>>>
> >>>> To fix this, call into eeti_ts_read() once to read the hardware status and
> >>>> to arm the IRQ again.
> >>>
> >>> Can you instead make the interrupt level-triggered?
> >>
> >> The hardware I'm working on doesn't support that unfortunately.
> >>
> >> In fact, the whole attn-gpio dance is there because of that, and the
> >> GPIO descriptor maps to the same pin that also causes the IRQ in my case.
> > 
> > OK, if the interrupt controller is incapable of dealing with level
> > interrupts then we have to do what you propose.
> 
> So you consider these patches for inclusion then? I'm just asking
> because I can't see them in your tree yet.

I was about to, but now I wonder if we need a mutex in the isr code now,
otherwise there is a chance it will be running concurrently when we are
resuming if interrupt does latch.

Thanks.

-- 
Dmitry