The fwnode_irq_get() and the fwnode_irq_get_byname() return 0 upon
device-tree IRQ mapping failure. This is contradicting the
fwnode_irq_get_byname() 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 make also the
fwnode_irq_get() follow same common convention returning a negative errno
upon failure.
Fixes: ca0acb511c21 ("device property: Add fwnode_irq_get_byname")
Suggested-by: Sakari Ailus <[email protected]>
Suggested-by: Jonathan Cameron <[email protected]>
Signed-off-by: Matti Vaittinen <[email protected]>
---
I dropped the existing reviewed-by tags because change to
fwnode_irq_get() was added.
Revision history:
v3 => v4:
- Change also the fwnode_irq_get()
---
drivers/base/property.c | 12 +++++++++---
1 file changed, 9 insertions(+), 3 deletions(-)
diff --git a/drivers/base/property.c b/drivers/base/property.c
index f6117ec9805c..8c40abed7852 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -987,12 +987,18 @@ EXPORT_SYMBOL(fwnode_iomap);
* @fwnode: Pointer to the firmware node
* @index: Zero-based index of the IRQ
*
- * Return: Linux IRQ number on success. Other values are determined
- * according to acpi_irq_get() or of_irq_get() operation.
+ * Return: Linux IRQ number on success. Negative errno on failure.
*/
int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
{
- return fwnode_call_int_op(fwnode, irq_get, index);
+ int ret;
+
+ ret = fwnode_call_int_op(fwnode, irq_get, index);
+ /* We treat mapping errors as invalid case */
+ if (ret == 0)
+ return -EINVAL;
+
+ return ret;
}
EXPORT_SYMBOL(fwnode_irq_get);
--
2.40.1
--
Matti Vaittinen, Linux device drivers
ROHM Semiconductors, Finland SWDC
Kiviharjunlenkki 1E
90220 OULU
FINLAND
~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
Simon says - in Latin please.
~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
Thanks to Simon Glass for the translation =]
Fri, May 19, 2023 at 02:00:54PM +0300, Matti Vaittinen kirjoitti:
> The fwnode_irq_get() and the fwnode_irq_get_byname() return 0 upon
> device-tree IRQ mapping failure. This is contradicting the
> fwnode_irq_get_byname() 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 make also the
> fwnode_irq_get() follow same common convention returning a negative errno
> upon failure.
Reviewed-by: Andy Shevchenko <[email protected]>
> Fixes: ca0acb511c21 ("device property: Add fwnode_irq_get_byname")
> Suggested-by: Sakari Ailus <[email protected]>
> Suggested-by: Jonathan Cameron <[email protected]>
> Signed-off-by: Matti Vaittinen <[email protected]>
>
> ---
> I dropped the existing reviewed-by tags because change to
> fwnode_irq_get() was added.
>
> Revision history:
> v3 => v4:
> - Change also the fwnode_irq_get()
> ---
> drivers/base/property.c | 12 +++++++++---
> 1 file changed, 9 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/base/property.c b/drivers/base/property.c
> index f6117ec9805c..8c40abed7852 100644
> --- a/drivers/base/property.c
> +++ b/drivers/base/property.c
> @@ -987,12 +987,18 @@ EXPORT_SYMBOL(fwnode_iomap);
> * @fwnode: Pointer to the firmware node
> * @index: Zero-based index of the IRQ
> *
> - * Return: Linux IRQ number on success. Other values are determined
> - * according to acpi_irq_get() or of_irq_get() operation.
> + * Return: Linux IRQ number on success. Negative errno on failure.
> */
> int fwnode_irq_get(const struct fwnode_handle *fwnode, unsigned int index)
> {
> - return fwnode_call_int_op(fwnode, irq_get, index);
> + int ret;
> +
> + ret = fwnode_call_int_op(fwnode, irq_get, index);
> + /* We treat mapping errors as invalid case */
> + if (ret == 0)
> + return -EINVAL;
Not sure if this is the best choice, perhaps -EEXIST or -ENOENT might be
better, but it's just a spoken up thought.
> + return ret;
> }
> EXPORT_SYMBOL(fwnode_irq_get);
--
With Best Regards,
Andy Shevchenko