Hi Janusz, On Tue, 3 Jul 2018 19:26:35 +0200 Janusz Krzysztofik <jmkrzy...@gmail.com> wrote:
> Avoid replication of error code conversion in non-DT GPIO consumers' > code by returning -EPROBE_DEFER from gpiod_find() in case a chip > identified by its label in a registered lookup table is not ready. > > See https://lkml.org/lkml/2018/5/30/176 for example case. > > Signed-off-by: Janusz Krzysztofik <jmkrzy...@gmail.com> > --- > If accepted, please add > Suggested-by: Boris Brezillon <boris.brezil...@bootlin.com> > if Boris doesn't mind. > > Thanks, > Janusz > > drivers/gpio/gpiolib.c | 13 ++++++++++--- > 1 file changed, 10 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c > index e11a3bb03820..15dc77c80328 100644 > --- a/drivers/gpio/gpiolib.c > +++ b/drivers/gpio/gpiolib.c > @@ -3639,9 +3639,16 @@ static struct gpio_desc *gpiod_find(struct device > *dev, const char *con_id, > chip = find_chip_by_name(p->chip_label); > > if (!chip) { > - dev_err(dev, "cannot find GPIO chip %s\n", > - p->chip_label); > - return ERR_PTR(-ENODEV); > + /* > + * As the lookup table indicates a chip with > + * p->chip_label should exist, assume it may > + * still appear latar and let the interested ^ later > + * consumer be probed again or let the Deferred > + * Probe infrastructure handle the error. > + */ > + dev_warn(dev, "cannot find GPIO chip %s, deferring\n", > + p->chip_label); > + return ERR_PTR(-EPROBE_DEFER); > } > > if (chip->ngpio <= p->chip_hwnum) { Looks good otherwise. Let's hope we're not breaking implementations testing for -ENODEV... Reviewed-by: Boris Brezillon <boris.brezil...@bootlin.com> Regards, Boris
