| Message ID | 1416900045-2304-1-git-send-email-acourbot@nvidia.com |
|---|---|
| State | Rejected |
| Headers | show |
Hello Alexandre, just some minor nitpicking on the commit log: On Tue, Nov 25, 2014 at 04:20:45PM +0900, Alexandre Courbot wrote: > Although gpiod_get_direction() can be considered side-effect free for > consumers, its internals involve setting or clearing bits in the > affected GPIO descriptor, for which we need to force-cast the const > descriptor parameter. This could lead to incorrect behavior is the s/ is/ if/, and I think s/parameter/variable to non-const/ > compiler decide to optimize here, so remove this const parameter. The s/decide/decides/; s/parameter/attribute/ > intent is to make gpiod_get_direction() private anyway, so it does not > really matter. > > Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks Uwe
On 11/25/2014 05:01 PM, Uwe Kleine-König wrote: > Hello Alexandre, > > just some minor nitpicking on the commit log: > > On Tue, Nov 25, 2014 at 04:20:45PM +0900, Alexandre Courbot wrote: >> Although gpiod_get_direction() can be considered side-effect free for >> consumers, its internals involve setting or clearing bits in the >> affected GPIO descriptor, for which we need to force-cast the const >> descriptor parameter. This could lead to incorrect behavior is the > s/ is/ if/, and I think s/parameter/variable to non-const/ > >> compiler decide to optimize here, so remove this const parameter. The > s/decide/decides/; s/parameter/attribute/ > >> intent is to make gpiod_get_direction() private anyway, so it does not >> really matter. >> >> Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> > Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Thanks ; I should have proof-read myself... Sending a v2 with a fixed log and your Ack so Linus can just pick the patch as-is. -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/gpio/gpiolib-sysfs.c b/drivers/gpio/gpiolib-sysfs.c index 781fbed00fc3..2ac1800b58bb 100644 --- a/drivers/gpio/gpiolib-sysfs.c +++ b/drivers/gpio/gpiolib-sysfs.c @@ -41,7 +41,7 @@ static DEFINE_MUTEX(sysfs_lock); static ssize_t gpio_direction_show(struct device *dev, struct device_attribute *attr, char *buf) { - const struct gpio_desc *desc = dev_get_drvdata(dev); + struct gpio_desc *desc = dev_get_drvdata(dev); ssize_t status; mutex_lock(&sysfs_lock); diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 5619922ebf44..0b271ef87c09 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -148,7 +148,7 @@ static int gpiochip_find_base(int ngpio) * * This function may sleep if gpiod_cansleep() is true. */ -int gpiod_get_direction(const struct gpio_desc *desc) +int gpiod_get_direction(struct gpio_desc *desc) { struct gpio_chip *chip; unsigned offset; @@ -164,13 +164,11 @@ int gpiod_get_direction(const struct gpio_desc *desc) if (status > 0) { /* GPIOF_DIR_IN, or other positive */ status = 1; - /* FLAG_IS_OUT is just a cache of the result of get_direction(), - * so it does not affect constness per se */ - clear_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); + clear_bit(FLAG_IS_OUT, &desc->flags); } if (status == 0) { /* GPIOF_DIR_OUT */ - set_bit(FLAG_IS_OUT, &((struct gpio_desc *)desc)->flags); + set_bit(FLAG_IS_OUT, &desc->flags); } return status; } diff --git a/include/linux/gpio/consumer.h b/include/linux/gpio/consumer.h index 83c0a61c605d..d54d158ca327 100644 --- a/include/linux/gpio/consumer.h +++ b/include/linux/gpio/consumer.h @@ -66,7 +66,7 @@ __devm_gpiod_get_index_optional(struct device *dev, const char *con_id, unsigned int index, enum gpiod_flags flags); void devm_gpiod_put(struct device *dev, struct gpio_desc *desc); -int gpiod_get_direction(const struct gpio_desc *desc); +int gpiod_get_direction(struct gpio_desc *desc); int gpiod_direction_input(struct gpio_desc *desc); int gpiod_direction_output(struct gpio_desc *desc, int value); int gpiod_direction_output_raw(struct gpio_desc *desc, int value);
Although gpiod_get_direction() can be considered side-effect free for consumers, its internals involve setting or clearing bits in the affected GPIO descriptor, for which we need to force-cast the const descriptor parameter. This could lead to incorrect behavior is the compiler decide to optimize here, so remove this const parameter. The intent is to make gpiod_get_direction() private anyway, so it does not really matter. Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Alexandre Courbot <acourbot@nvidia.com> --- drivers/gpio/gpiolib-sysfs.c | 2 +- drivers/gpio/gpiolib.c | 8 +++----- include/linux/gpio/consumer.h | 2 +- 3 files changed, 5 insertions(+), 7 deletions(-)