[PATCH 6.4 627/800] drivers: fwnode: fix fwnode_irq_get[_byname]()

Greg Kroah-Hartman
2023-07-16T20:23:36Z

From: Matti Vaittinen <mazziesaccount@gmail.com>

[ Upstream commit 39d422555e43379516d4d13f5b7162a3dee6e646 ]

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 <sakari.ailus@linux.intel.com>
Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

Message-ID: <3e64fe592dc99e27ef9a0b247fc49fa26b6b8a58.1685340157.git.mazziesaccount@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f6117ec9805c4..8c40abed78524 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);

--
2.39.2