[PATCH v9 5/5] PCI: of: Remove max-link-speed generation validation

Hans Zhang 18255117159 at 163.com
Fri Mar 13 09:55:22 PDT 2026


The of_pci_get_max_link_speed() function currently validates the
"max-link-speed" DT property to be in the range 1..4 (Gen1..Gen4).
This imposes a maintenance burden because each new PCIe generation
would require updating this validation.

Remove the range check so the function returns the raw property value
(or a negative error code if the property is missing or malformed).
Callers must now validate the returned speed against the range they
support. A subsequent patch adds such validation to the DWC driver,
which is the primary user of this function.

Removing the validation from this common function allows future PCIe
generations to be supported without modifying drivers/pci/of.c.

Signed-off-by: Hans Zhang <18255117159 at 163.com>
---
 drivers/pci/of.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 9f8eb5df279e..d645041f5125 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -875,24 +875,24 @@ EXPORT_SYMBOL_GPL(of_pci_supply_present);
  * of_pci_get_max_link_speed - Find the maximum link speed of the given device node.
  * @node: Device tree node with the maximum link speed information.
  *
- * This function will try to find the limitation of link speed by finding
- * a property called "max-link-speed" of the given device node.
+ * This function will try to read the "max-link-speed" property of the given
+ * device tree node. It does NOT validate the value of the property.
  *
  * Return:
  * * > 0	- On success, a maximum link speed.
- * * -EINVAL	- Invalid "max-link-speed" property value, or failure to access
- *		  the property of the device tree node.
+ * * -EINVAL	- Failure to access the property of the device tree node.
  *
  * Returns the associated max link speed from DT, or a negative value if the
- * required property is not found or is invalid.
+ * required property is not found.
  */
 int of_pci_get_max_link_speed(struct device_node *node)
 {
 	u32 max_link_speed;
+	int ret;
 
-	if (of_property_read_u32(node, "max-link-speed", &max_link_speed) ||
-	    max_link_speed == 0 || max_link_speed > 4)
-		return -EINVAL;
+	ret = of_property_read_u32(node, "max-link-speed", &max_link_speed);
+	if (ret)
+		return ret;
 
 	return max_link_speed;
 }
-- 
2.34.1




More information about the Linux-mediatek mailing list