On Wed, May 15, 2019 at 09:54:17PM +0200, Daniel Mack wrote:
> On 14/5/2019 5:12 AM, Dmitry Torokhov wrote:
> > Hi Daniel,
> >
> > On Mon, May 06, 2019 at 04:52:19PM +0200, Daniel Mack wrote:
> >> Hi Dmitry,
> >>
> >> Is this one good to go in? WDYT?
> >
> > I wonder if we should combine the 2 and have something like below.
>
> Sure, looks fine to me, except for one small yet important thing - see
> below.
>
>
>
> > Input: eeti_ts - read hardware state once after wakeup
> >
> > From: Daniel Mack <daniel@xxxxxxxxxx>
> >
> > For systems in which the touch IRQ is acting as wakeup source, and that do
> > not support level-driven interrupts, 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, check for the assertion of the attn gpio, and read form the
> > controller once in the resume path to read the hardware status and
> > to arm the IRQ again.
> >
> > Introduce a mutex to guard eeti_ts_read() against parallel invocations
> > from different contexts.
> >
> > Signed-off-by: Daniel Mack <daniel@xxxxxxxxxx>
> > Reported-by: Sven Neumann <Sven.Neumann@xxxxxxxxx>
> > Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
> > ---
> > drivers/input/touchscreen/eeti_ts.c | 71 ++++++++++++++++++++++++++++-------
> > 1 file changed, 56 insertions(+), 15 deletions(-)
>
> [...]
>
> > static void eeti_ts_start(struct eeti_ts *eeti)
> > {
> > + mutex_lock(&eeti->mutex);
> > +
> > eeti->running = true;
> > - wmb();
> > enable_irq(eeti->client->irq);
> > +
> > + /*
> > + * Kick the controller in case we are using edge interrupt and
> > + * we missed our edge while interrupt was disabled. We expect
> > + * the attention GPIO to be wired in this case.
> > + */
> > + if (eeti->attn_gpio && gpiod_get_value_cansleep(eeti->attn_gpio))
> > + eeti_ts_read(eeti);
> > +
> > + mutex_lock(&eeti->mutex);
>
> If you turn the above into a mutex_unlock(), I'm happy :)
*sigh* I so wanted to save 2 bytes here ;)
Thanks for spotting this.
--
Dmitry
