Thread (18 messages) 18 messages, 3 authors, 2023-05-28

Re: [PATCH v5 1/8] drivers: fwnode: fix fwnode_irq_get[_byname]()

From: <hidden>
Date: 2023-05-21 17:35:24
Also in: linux-acpi, linux-gpio, linux-i2c, linux-iio, linux-mips, lkml

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 <redacted>
quoted hunk ↗ jump to hunk
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>

---
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

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