[PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

[PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

[Grigoryev Denis]

The driver stores the result of irq_set_type() in the internal variables
irq_trig_raise and irq_trig_fall, which later are used to determine
the GPIOs that must be re-configured as input. These variables retain their
value between gpiolib's  export / unexport, resulting in an incorrect
state in some cases. The corresponding bits in the variables
irq_trig_raise and irq_trig_fall should be cleared in irq_shutdown().

Signed-off-by: Denis Grigoryev <grigoryev@fastwel.ru>
---
 drivers/gpio/gpio-pca953x.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
index d2ead4b..b41be8c 100644
--- a/drivers/gpio/gpio-pca953x.c
+++ b/drivers/gpio/gpio-pca953x.c
@@ -522,6 +522,15 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
 	return 0;
 }
 
+static void pca953x_irq_shutdown(struct irq_data *d)
+{
+	struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
+	u8 mask = 1 << (d->hwirq % BANK_SZ);
+
+	chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
+	chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
+}
+
 static struct irq_chip pca953x_irq_chip = {
 	.name			= "pca953x",
 	.irq_mask		= pca953x_irq_mask,
@@ -529,6 +538,7 @@ static struct irq_chip pca953x_irq_chip = {
 	.irq_bus_lock		= pca953x_irq_bus_lock,
 	.irq_bus_sync_unlock	= pca953x_irq_bus_sync_unlock,
 	.irq_set_type		= pca953x_irq_set_type,
+	.irq_shutdown		= pca953x_irq_shutdown,
 };
 
 static bool pca953x_irq_pending(struct pca953x_chip *chip, u8 *pending)
-- 
2.7.4

Re: [PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

[Linus Walleij]

On Fri, May 4, 2018 at 6:53 PM, Grigoryev Denis <grigoryev@fastwel.ru> wrote:

> The driver stores the result of irq_set_type() in the internal variables
> irq_trig_raise and irq_trig_fall, which later are used to determine
> the GPIOs that must be re-configured as input. These variables retain their
> value between gpiolib's  export / unexport, resulting in an incorrect
> state in some cases. The corresponding bits in the variables
> irq_trig_raise and irq_trig_fall should be cleared in irq_shutdown().
>
> Signed-off-by: Denis Grigoryev <grigoryev@fastwel.ru>
> ---
>  drivers/gpio/gpio-pca953x.c | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-pca953x.c
> index d2ead4b..b41be8c 100644
> --- a/drivers/gpio/gpio-pca953x.c
> +++ b/drivers/gpio/gpio-pca953x.c
> @@ -522,6 +522,15 @@ static int pca953x_irq_set_type(struct irq_data *d, unsigned int type)
>         return 0;
>  }
>
> +static void pca953x_irq_shutdown(struct irq_data *d)
> +{
> +       struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
> +       u8 mask = 1 << (d->hwirq % BANK_SZ);
> +
> +       chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
> +       chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
> +}
> +
>  static struct irq_chip pca953x_irq_chip = {
>         .name                   = "pca953x",
>         .irq_mask               = pca953x_irq_mask,
> @@ -529,6 +538,7 @@ static struct irq_chip pca953x_irq_chip = {
>         .irq_bus_lock           = pca953x_irq_bus_lock,
>         .irq_bus_sync_unlock    = pca953x_irq_bus_sync_unlock,
>         .irq_set_type           = pca953x_irq_set_type,
> +       .irq_shutdown           = pca953x_irq_shutdown,
>  };

This driver has a big set of users, so putting some maintainers
in the loop so we can get some patch review.

Yours,
Linus Walleij

Re: [PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

[Andy Shevchenko]

On Wed, 2018-05-16 at 14:51 +0200, Linus Walleij wrote:
> On Fri, May 4, 2018 at 6:53 PM, Grigoryev Denis <grigoryev@fastwel.ru>
> wrote:
> 

If it's full context below, the patch looks good enough to me (assuming
it works and doesn't break things on other chips like PCAL variants).

Though, I didn't read the code carefully (not enough time this week).
Thus, FWIW, 

Acked-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

with above caveats in mind.

> > The driver stores the result of irq_set_type() in the internal
> > variables
> > irq_trig_raise and irq_trig_fall, which later are used to determine
> > the GPIOs that must be re-configured as input. These variables
> > retain their
> > value between gpiolib's  export / unexport, resulting in an
> > incorrect
> > state in some cases. The corresponding bits in the variables
> > irq_trig_raise and irq_trig_fall should be cleared in
> > irq_shutdown().
> > 
> > Signed-off-by: Denis Grigoryev <grigoryev@fastwel.ru>
> > ---
> >  drivers/gpio/gpio-pca953x.c | 10 ++++++++++
> >  1 file changed, 10 insertions(+)
> > 
> > diff --git a/drivers/gpio/gpio-pca953x.c b/drivers/gpio/gpio-
> > pca953x.c
> > index d2ead4b..b41be8c 100644
> > --- a/drivers/gpio/gpio-pca953x.c
> > +++ b/drivers/gpio/gpio-pca953x.c
> > @@ -522,6 +522,15 @@ static int pca953x_irq_set_type(struct irq_data
> > *d, unsigned int type)
> >         return 0;
> >  }
> > 
> > +static void pca953x_irq_shutdown(struct irq_data *d)
> > +{
> > +       struct pca953x_chip *chip = irq_data_get_irq_chip_data(d);
> > +       u8 mask = 1 << (d->hwirq % BANK_SZ);
> > +
> > +       chip->irq_trig_raise[d->hwirq / BANK_SZ] &= ~mask;
> > +       chip->irq_trig_fall[d->hwirq / BANK_SZ] &= ~mask;
> > +}
> > +
> >  static struct irq_chip pca953x_irq_chip = {
> >         .name                   = "pca953x",
> >         .irq_mask               = pca953x_irq_mask,
> > @@ -529,6 +538,7 @@ static struct irq_chip pca953x_irq_chip = {
> >         .irq_bus_lock           = pca953x_irq_bus_lock,
> >         .irq_bus_sync_unlock    = pca953x_irq_bus_sync_unlock,
> >         .irq_set_type           = pca953x_irq_set_type,
> > +       .irq_shutdown           = pca953x_irq_shutdown,
> >  };
> 
> This driver has a big set of users, so putting some maintainers
> in the loop so we can get some patch review.
> 
> Yours,
> Linus Walleij

-- 
Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Intel Finland Oy

Re: [PATCH] gpio: pca953x: Clear irq trigger type on irq shutdown

[Linus Walleij]

On Fri, May 4, 2018 at 6:53 PM, Grigoryev Denis <grigoryev@fastwel.ru> wrote:

> The driver stores the result of irq_set_type() in the internal variables
> irq_trig_raise and irq_trig_fall, which later are used to determine
> the GPIOs that must be re-configured as input. These variables retain their
> value between gpiolib's  export / unexport, resulting in an incorrect
> state in some cases. The corresponding bits in the variables
> irq_trig_raise and irq_trig_fall should be cleared in irq_shutdown().
>
> Signed-off-by: Denis Grigoryev <grigoryev@fastwel.ru>

Patch applied with Andy's ACK.

If there are issues we can just revert it.

Yours,
Linus Walleij