[PATCH v3 1/3] drivers: fwnode: fix fwnode_irq_get_byname()

Matti Vaittinen
2023-05-12T07:53:25Z

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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@linux.intel.com>
Reviewed-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
---
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 f6117ec9805c..a3b95d2d781f 100644
--- a/drivers/base/property.c
+++ b/drivers/base/property.c
@@ -1011,7 +1011,7 @@ 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;
@@ -1020,7 +1020,12 @@ 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);
+ /* We treat mapping errors as invalid case */
+ if (ret == 0)
+ return -EINVAL;
+
+ return ret;
}
EXPORT_SYMBOL(fwnode_irq_get_byname);