Re: [PATCH net] net: macb: drop CONFIG_OF #if block

Fix -Wimplicit-function-declaration error on CONFIG_OF=n builds:

  drivers/net/ethernet/cadence/macb_main.c: In function ‘macb_probe’:
  drivers/net/ethernet/cadence/macb_main.c:5951:15: error: implicit
  declaration of function ‘macb_alloc_tieoff’ [...]
   5951 |         err = macb_alloc_tieoff(bp);
        |               ^~~~~~~~~~~~~~~~~
  drivers/net/ethernet/cadence/macb_main.c:5973:9: error: implicit
  declaration of function ‘macb_free_tieoff’ [...]
   5973 |         macb_free_tieoff(bp);
        |         ^~~~~~~~~~~~~~~~

Error got introduced because functions are mistakenly declared in a
`#if defined(CONFIG_OF)` block. Instead of moving functions around,
avoid any future mistake and drop the block entirely.

Change the module content slightly on CONFIG_OF=n. Previously match
tables were ignored. Now they appear in the resulting build. This is
considered trivial in size by most and is the common case:

  ⟩ 18 out of 254 OF net drivers reference CONFIG_OF
  ⟩ rg -lF 'MODULE_DEVICE_TABLE(of,' drivers/net/ | tee /tmp/a | wc -l
  254
  ⟩ xargs -a /tmp/a rg -l CONFIG_OF | wc -l
  18

Tangent: no, of_match_ptr() does not imply that the compiler can
optimize out match tables, because MODULE_DEVICE_TABLE(of, ...)
unconditionally puts the match tables in the binary. It is only meant
to avoid undefined declaration issues when match tables are hidden
behind a #ifdef, as was done before. We therefore drop the macro call.

Fixes: 5262eab9462a ("net: macb: allocate tieoff descriptor once across device lifetime")
Signed-off-by: Théo Lebrun <theo.lebrun@bootlin.com>
---
This is a fix to a build issue present on net/main (91ec20351349) and
linux-next/master(7079a12d7506). The problematic just landed in
net/main.

Two fixes [0][1] were sent previously (both the same solution):
[PATCH net] net: macb: Move macb_{alloc,free}_tieoff() out of CONFIG_OF block
[PATCH net-next] net: macb: fix CONFIG_OF=n build

Instead I'm suggesting [2] we drop the error-prone preprocessor blocks
and do as everyone else.

[0]: https://lore.kernel.org/netdev/20260818-macb-fix-no-of-build-v1-1-f2a009616384@kernel.org/ (local)
[1]: https://lore.kernel.org/netdev/20260819040913.109367-1-running910@gmail.com/ (local)
[2]: https://lore.kernel.org/netdev/DKT4CBU8YB5G.2W0766H2NU6Y8@bootlin.com/ (local)
---
drivers/net/ethernet/cadence/macb_main.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/cadence/macb_main.c b/drivers/net/ethernet/cadence/macb_main.c
index 1476bce77f34..76ee4f506033 100644
--- a/drivers/net/ethernet/cadence/macb_main.c
+++ b/drivers/net/ethernet/cadence/macb_main.c

@@ -4926,7 +4926,6 @@ static const struct macb_usrio_config at91_default_usrio = {

	.clken = MACB_BIT(CLKEN),
};

-#if defined(CONFIG_OF)
/* 1518 rounded up */
#define AT91ETHER_MAX_RBUFF_SZ	0x600
/* max number of receive buffers */

@@ -5754,7 +5753,6 @@ static const struct of_device_id macb_dt_ids[] = {

	{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, macb_dt_ids);
-#endif /* CONFIG_OF */

static const struct macb_config default_gem_config = {
	.caps = MACB_CAPS_GIGABIT_MODE_AVAILABLE |

@@ -6267,7 +6265,7 @@ static struct platform_driver macb_driver = {

	.remove		= macb_remove,
	.driver		= {
		.name		= "macb",
-		.of_match_table	= of_match_ptr(macb_dt_ids),
+		.of_match_table	= macb_dt_ids,
		.pm	= &macb_pm_ops,
	},
	.shutdown	= macb_shutdown,

---
base-commit: 91ec2035134982b98fab0609a9fd8480e8217dc1
change-id: 20260820-macb-fix-x86-eb78a1fcc63e

Best regards,
--  
Théo Lebrun [off-list ref]