2022-05-18 09:04:41

by Geert Uytterhoeven

Subject: [PATCH] net: smc911x: Fix min() use in debug code

If ENABLE_SMC_DEBUG_PKTS=1:

drivers/net/ethernet/smsc/smc911x.c: In function ‘smc911x_hardware_send_pkt’:
include/linux/minmax.h:20:28: error: comparison of distinct pointer types lacks a cast [-Werror]
20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
| ^~
drivers/net/ethernet/smsc/smc911x.c:483:17: note: in expansion of macro ‘min’
483 | PRINT_PKT(buf, min(len, 64));

Fix this by making the constant unsigned, to match the type of "len".
While at it, replace the other missed ternary operator by min(), too.

Convert the dummy PRINT_PKT() from a macro to a static inline function,
to catch mistakes like this without having to enable debug options
manually.

Fixes: 5ff0348b7f755aac ("net: smc911x: replace ternary operator with min()")
Signed-off-by: Geert Uytterhoeven <[email protected]>
---
drivers/net/ethernet/smsc/smc911x.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/net/ethernet/smsc/smc911x.c b/drivers/net/ethernet/smsc/smc911x.c
index 2694287770e6cd8e..24d66af797d465ca 100644
--- a/drivers/net/ethernet/smsc/smc911x.c
+++ b/drivers/net/ethernet/smsc/smc911x.c
@@ -140,7 +140,7 @@ static void PRINT_PKT(u_char *buf, int length)
pr_cont("\n");
}
#else
-#define PRINT_PKT(x...) do { } while (0)
+static inline void PRINT_PKT(u_char *buf, int length) { }
#endif


@@ -430,7 +430,7 @@ static inline void smc911x_rcv(struct net_device *dev)
SMC_PULL_DATA(lp, data, pkt_len+2+3);

DBG(SMC_DEBUG_PKTS, dev, "Received packet\n");
- PRINT_PKT(data, ((pkt_len - 4) <= 64) ? pkt_len - 4 : 64);
+ PRINT_PKT(data, min(pkt_len - 4, 64U));
skb->protocol = eth_type_trans(skb, dev);
netif_rx(skb);
dev->stats.rx_packets++;
@@ -480,7 +480,7 @@ static void smc911x_hardware_send_pkt(struct net_device *dev)
SMC_SET_TX_FIFO(lp, cmdB);

DBG(SMC_DEBUG_PKTS, dev, "Transmitted packet\n");
- PRINT_PKT(buf, min(len, 64));
+ PRINT_PKT(buf, min(len, 64U));

/* Send pkt via PIO or DMA */
#ifdef SMC_USE_DMA
--
2.25.1

2022-05-18 13:21:25

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] net: smc911x: Fix min() use in debug code

Hello:

This patch was applied to netdev/net-next.git (master)
by David S. Miller <[email protected]>:

On Wed, 18 May 2022 11:04:19 +0200 you wrote:
> If ENABLE_SMC_DEBUG_PKTS=1:
>
> drivers/net/ethernet/smsc/smc911x.c: In function ‘smc911x_hardware_send_pkt’:
> include/linux/minmax.h:20:28: error: comparison of distinct pointer types lacks a cast [-Werror]
> 20 | (!!(sizeof((typeof(x) *)1 == (typeof(y) *)1)))
> | ^~
> drivers/net/ethernet/smsc/smc911x.c:483:17: note: in expansion of macro ‘min’
> 483 | PRINT_PKT(buf, min(len, 64));
>
> [...]

Here is the summary with links:
- net: smc911x: Fix min() use in debug code
https://git.kernel.org/netdev/net-next/c/a3641ca416a3

You are awesome, thank you!
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