Moi,
On Tue, Oct 25, 2022 at 11:50:59AM +0300, Matti Vaittinen wrote:
> The fwnode_irq_get_byname() does return 0 upon device-tree IRQ mapping
> failure. This is contradicting the function documentation and can
> potentially be a source of errors like:
>
> int probe(...) {
> ...
>
> irq = fwnode_irq_get_byname();
> if (irq <= 0)
> return irq;
>
> ...
> }
>
> Here we do correctly check the return value from fwnode_irq_get_byname()
> but the driver probe will now return success. (There was already one
> such user in-tree).
>
> Change the fwnode_irq_get_byname() to work as documented and according to
> the common convention and abd always return a negative errno upon failure.
>
> Fixes: ca0acb511c21 ("device property: Add fwnode_irq_get_byname")
> Suggested-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> Signed-off-by: Matti Vaittinen <mazziesaccount@xxxxxxxxx>
>
> ---
>
> I did a quick audit for the callers at v6.1-rc2:
> drivers/i2c/i2c-smbus.c
> drivers/iio/accel/adxl355_core.c
> drivers/iio/gyro/fxas21002c_core.c
> drivers/iio/imu/adis16480.c
> drivers/iio/imu/bmi160/bmi160_core.c
> drivers/iio/imu/bmi160/bmi160_core.c
>
> I did not spot any errors to be caused by this change. There will be a
It won't as you're decreasing the possible values the function may
return...
> functional change in i2c-smbus.c as the probe will now return -EINVAL
> should the IRQ dt-mapping fail. It'd be nice if this was checked to be
> Ok by the peeps knowing the i2c-smbus :)
FWIW, for both patches (but see below):
Reviewed-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
> ---
> drivers/base/property.c | 9 +++++++--
> 1 file changed, 7 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index 4d6278a84868..bfc6c7286db2 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -964,7 +964,7 @@ EXPORT_SYMBOL(fwnode_irq_get);
> */
> int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name)
> {
> - int index;
> + int index, ret;
>
> if (!name)
> return -EINVAL;
> @@ -973,7 +973,12 @@ int fwnode_irq_get_byname(const struct fwnode_handle *fwnode, const char *name)
> if (index < 0)
> return index;
>
> - return fwnode_irq_get(fwnode, index);
> + ret = fwnode_irq_get(fwnode, index);
> +
This newline is extra.
Or:
return ret ?: -EINVAL;
Or even:
return fwnode_irq_get(fwnode, index) ?: -EINVAL;
Up to you.
> + if (!ret)
> + return -EINVAL;
> +
> + return ret;
> }
> EXPORT_SYMBOL(fwnode_irq_get_byname);
--
Terveisin,
Sakari Ailus
