On Fri, Feb 20, 2015 at 9:30 AM, Dmitry Torokhov <dmitry.torok...@gmail.com> wrote: > Given the intent behind gpiod_get_optional() and friends it does not make > sense to return -ENOSYS when GPIOLIB is disabled: the driver is expected to > work just fine without gpio so let's behave as if gpio was not found. > Otherwise we have to special-case -ENOSYS in drivers.
Interestingly Uwe sent a RFC for this one week ago: http://patchwork.ozlabs.org/patch/439135/ Maybe credit him with a Suggested-by.? I should have commented at that time, but let's do it now: I agree with the idea, but this leaves the door open to confusing situations in case gpiolib was unintentionally disabled. Could you also add a note in the documentation of this function to explain this behavior, to spare a few headaches to users of this function? > > Signed-off-by: Dmitry Torokhov <dmitry.torok...@gmail.com> > --- > include/linux/gpio/consumer.h | 8 ++++---- > 1 file changed, 4 insertions(+), 4 deletions(-) > > diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h > index fd85cb1..f68244f 100644 > --- a/include/linux/gpio/consumer.h > +++ b/include/linux/gpio/consumer.h > @@ -132,14 +132,14 @@ static inline struct gpio_desc *__must_check > __gpiod_get_optional(struct device *dev, const char *con_id, > enum gpiod_flags flags) > { > - return ERR_PTR(-ENOSYS); > + return NULL; > } > > static inline struct gpio_desc *__must_check > __gpiod_get_index_optional(struct device *dev, const char *con_id, > unsigned int index, enum gpiod_flags flags) > { > - return ERR_PTR(-ENOSYS); > + return NULL; > } > > static inline void gpiod_put(struct gpio_desc *desc) > @@ -171,14 +171,14 @@ static inline struct gpio_desc *__must_check > __devm_gpiod_get_optional(struct device *dev, const char *con_id, > enum gpiod_flags flags) > { > - return ERR_PTR(-ENOSYS); > + return NULL; > } > > static inline struct gpio_desc *__must_check > __devm_gpiod_get_index_optional(struct device *dev, const char *con_id, > unsigned int index, enum gpiod_flags flags) > { > - return ERR_PTR(-ENOSYS); > + return NULL; > } > > static inline void devm_gpiod_put(struct device *dev, struct gpio_desc *desc) > -- > 2.2.0.rc0.207.ga3a616c > > > -- > Dmitry -- 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/
