[PATCHv2 net-next] net: fec_mpc52xx: remove dead resource size check

[PATCHv2 net-next] net: fec_mpc52xx: remove dead resource size check

[Rosen Penev]

The check bails out if the FEC register resource is smaller than
sizeof(struct mpc52xx_fec), but every in-tree device tree describes
the FEC node as a 0x400 byte region, which is exactly the size of the
struct, so the condition can never be true.

The error message also points at mpc52xx_devices.c, which was removed
in 2008 by commit 917f0af9e5a9 ("powerpc: Remove arch/ppc and
include/asm-ppc").

Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 v2: instead of fixing format, remove the dead check.
 drivers/net/ethernet/freescale/fec_mpc52xx.c | 7 -------
 1 file changed, 7 deletions(-)

diff --git a/drivers/net/ethernet/freescale/fec_mpc52xx.c b/drivers/net/ethernet/freescale/fec_mpc52xx.c
index 90379c26f300..dcf378a02835 100644
--- a/drivers/net/ethernet/freescale/fec_mpc52xx.c
+++ b/drivers/net/ethernet/freescale/fec_mpc52xx.c
@@ -834,13 +834,6 @@ static int mpc52xx_fec_probe(struct platform_device *op)
 		pr_err("Error while parsing device node resource\n");
 		goto err_netdev;
 	}
-	if (resource_size(&mem) < sizeof(struct mpc52xx_fec)) {
-		pr_err("invalid resource size (%lx < %x), check mpc52xx_devices.c\n",
-		       (unsigned long)resource_size(&mem),
-		       sizeof(struct mpc52xx_fec));
-		rv = -EINVAL;
-		goto err_netdev;
-	}
 
 	if (!request_mem_region(mem.start, sizeof(struct mpc52xx_fec),
 				DRIVER_NAME)) {
-- 
2.55.0

Re: [PATCHv2 net-next] net: fec_mpc52xx: remove dead resource size check

[Andrew Lunn]

On Wed, Sep 16, 2026 at 03:32:28PM -0700, Rosen Penev wrote:
> The check bails out if the FEC register resource is smaller than
> sizeof(struct mpc52xx_fec), but every in-tree device tree describes
> the FEC node as a 0x400 byte region, which is exactly the size of the
> struct, so the condition can never be true.

We generally don't fully trust DT blobs.

Does this test do any actual harm in its current state?
Why remove it?

	Andrew

Re: [PATCHv2 net-next] net: fec_mpc52xx: remove dead resource size check

[Rosen Penev]

On Thu, Sep 17, 2026 at 7:56 AM Andrew Lunn <andrew@lunn.ch> wrote:
>
> On Wed, Sep 16, 2026 at 03:32:28PM -0700, Rosen Penev wrote:
> > The check bails out if the FEC register resource is smaller than
> > sizeof(struct mpc52xx_fec), but every in-tree device tree describes
> > the FEC node as a 0x400 byte region, which is exactly the size of the
> > struct, so the condition can never be true.
>
> We generally don't fully trust DT blobs.
>
> Does this test do any actual harm in its current state?
> Why remove it?
Previous discussion:

https://lore.kernel.org/netdev/20260518044047.1002235-1-rosenp@gmail.com/
>
>         Andrew