On Thu, Sep 15, 2016 at 05:07:58PM +0100, Marc Zyngier wrote:
> Mika,
>
> On 15/09/16 16:52, Mika Westerberg wrote:
> > When using GPIO irqchip helpers to setup irqchip for a gpiolib based
> > driver, it is not possible to select which GPIOs to add to the IRQ domain.
> > Instead it just adds all GPIOs which is not always desired. For example
> > there might be GPIOs that for some reason just cannot be used as interrupts
> > at all.
> >
> > To make this possible we add valid_mask to each gpio_chip and by default
> > assume all GPIOs can be used as interrupts. Drivers can then tune this
> > using clear_bit() or similar before they call gpiochip_irqchip_add().
> >
> > Suggested-by: Linus Walleij <linus.wall...@linaro.org>
> > Signed-off-by: Mika Westerberg <mika.westerb...@linux.intel.com>
> > ---
> > drivers/gpio/gpiolib.c | 32 +++++++++++++++++++++++++++++---
> > include/linux/gpio/driver.h | 1 +
> > 2 files changed, 30 insertions(+), 3 deletions(-)
> >
> > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> > index 53ff25ac66d8..d84c23b47f44 100644
> > --- a/drivers/gpio/gpiolib.c
> > +++ b/drivers/gpio/gpiolib.c
> > @@ -1186,6 +1186,18 @@ int gpiochip_add_data(struct gpio_chip *chip, void
> > *data)
> > if (status)
> > goto err_remove_chip;
> > }
> > +
> > +#ifdef CONFIG_GPIOLIB_IRQCHIP
> > + chip->valid_mask = kcalloc(BITS_TO_LONGS(chip->ngpio), sizeof(long),
> > + GFP_KERNEL);
>
> Do we really want to make this a mandatory thing? In most cases, I'd
> expect this valid_mask to have all bits set, so you might as well not
> allocate it at all in that case (and only allocate it if you actually
> need it).
We can make drivers to allocate it and only if set use it in core.
>
> > + if (!chip->valid_mask)
> > + return -ENOMEM;
>
> You really want to revise your error handling here.
Oops, right. It should be:
if (!chip->valid_mask) {
status = -ENOMEM;
goto err_remove_chip;
}
