On Fri 28 Aug 09:44 PDT 2015, Bjorn Andersson wrote:
> It's possible to have gpio chips hanging off unreliable remote buses
> where the get() operation will fail to acquire a readout of the current
> gpio state. Propagate these errors to the consumer so that they can
> act on, retry or ignore these failing reads, instead of treating them as
> the line being held high.
>
> Signed-off-by: Bjorn Andersson <bjorn.anders...@sonymobile.com>
> ---
> drivers/gpio/gpiolib.c | 21 ++++++++++++++-------
> 1 file changed, 14 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c
> index 3b5e516298e0..dc17dbf8c234 100644
> --- a/drivers/gpio/gpiolib.c
> +++ b/drivers/gpio/gpiolib.c
> @@ -1173,15 +1173,16 @@ EXPORT_SYMBOL_GPL(gpiod_is_active_low);
> * that the GPIO was actually requested.
> */
>
> -static bool _gpiod_get_raw_value(const struct gpio_desc *desc)
> +static int _gpiod_get_raw_value(const struct gpio_desc *desc)
> {
> struct gpio_chip *chip;
> - bool value;
> int offset;
> + int value;
>
> chip = desc->chip;
> offset = gpio_chip_hwgpio(desc);
> - value = chip->get ? chip->get(chip, offset) : false;
> + value = chip->get ? chip->get(chip, offset) : -EIO;
Linus, Alexandre, please feel free to apply this with -ENOTSUPP in
accordance to Alexandre's comment in [1], if you prefer that. I picked
-EIO as that's what's used in most other places when the get() op is
missing.
Maybe we should follow up with separate patch to make that consistent?
[1] https://lkml.org/lkml/2015/8/31/8
> + value = value < 0 ? value : !!value;
> trace_gpio_value(desc_to_gpio(desc), 1, value);
> return value;
> }
Regards,
Bjorn
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
