[PATCH v8 5/5] PCI: of: Remove max-link-speed generation validation

Hans Zhang
2026-03-12T16:38:19Z

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@163.com>
---
drivers/pci/of.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/of.c b/drivers/pci/of.c
index 9f8eb5df279e..fbb779a94202 100644
--- a/drivers/pci/of.c
+++ b/drivers/pci/of.c
@@ -875,8 +875,9 @@ 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 (e.g.,
+ * range checks for PCIe generations).
*
* Return:
* * > 0 - On success, a maximum link speed.
@@ -889,10 +890,11 @@ EXPORT_SYMBOL_GPL(of_pci_supply_present);
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