[PATCH] net: mdio: fix -Wvoid-pointer-to-enum-cast warning

From: Justin Stitt
Date: Tue Aug 15 2023 - 16:37:15 EST


When building with clang 18 I see the following warning:
| drivers/net/mdio/mdio-xgene.c:338:13: warning: cast to smaller integer
| type 'enum xgene_mdio_id' from 'const void *' [-Wvoid-pointer-to-enum-cast]
| 338 | mdio_id = (enum xgene_mdio_id)of_id->data;

This is due to the fact that `of_id->data` is a void* while `enum
xgene_mdio_id` has the size of an int. This leads to truncation and
possible data loss.

Link: https://github.com/ClangBuiltLinux/linux/issues/1910
Reported-by: Nathan Chancellor <nathan@xxxxxxxxxx>
Signed-off-by: Justin Stitt <justinstitt@xxxxxxxxxx>
---
Note: `xgene_mdio_id` has only two fields enumerated from 1 which means
this is no data loss happening here. Either way, this patch helps the
goal of eventually enabling this warning for more builds by reducing
noise.
---
drivers/net/mdio/mdio-xgene.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/mdio/mdio-xgene.c b/drivers/net/mdio/mdio-xgene.c
index 7aafc221b5cf..7119eb11c00d 100644
--- a/drivers/net/mdio/mdio-xgene.c
+++ b/drivers/net/mdio/mdio-xgene.c
@@ -335,7 +335,7 @@ static int xgene_mdio_probe(struct platform_device *pdev)

of_id = of_match_device(xgene_mdio_of_match, &pdev->dev);
if (of_id) {
- mdio_id = (enum xgene_mdio_id)of_id->data;
+ mdio_id = (uintptr_t)of_id->data;
} else {
#ifdef CONFIG_ACPI
const struct acpi_device_id *acpi_id;

---
base-commit: 2ccdd1b13c591d306f0401d98dedc4bdcd02b421
change-id: 20230815-void-drivers-net-mdio-mdio-xgene-e5b3b4a3343b

Best regards,
--
Justin Stitt <justinstitt@xxxxxxxxxx>