[PATCH] net: tulip: Remove private "strncmp"

From: Rasmus Villemoes
Date: Thu Dec 04 2014 - 05:31:13 EST

The comment says that the built-in strncmp didn't work. That is not
surprising, as apparently "str" semantics are not really what is
wanted (hint: de4x5_strncmp only stops when two different bytes are
encountered or the end is reached; not if either byte happens to be
0). de4x5_strncmp is actually a memcmp (except for the signature and
that bytes are not necessarily treated as unsigned char); since only
the boolean value of the result is used we can just replace
de4x5_strncmp with memcmp.

Signed-off-by: Rasmus Villemoes <linux@xxxxxxxxxxxxxxxxxx>

I don't know if the comment meant to say 3 bytes, or if the code
compares meaningful chunks of memory (the first three bytes of
&lp->srom span 1.5 fields, and the three bytes from (char*)&lp->srom +
0x10 are &lp->srom.{id_block_crc,reserved2,version} - it seems odd
that these chunks should ever be equal to each other and to the
enet_det[i]). Whether or not the current code works, this patch
shouldn't change the semantics, and I'd like to get rid of
de4x5_strncmp since it is not, in fact, a strncmp.

drivers/net/ethernet/dec/tulip/de4x5.c | 20 +++-----------------
1 file changed, 3 insertions(+), 17 deletions(-)

diff --git a/drivers/net/ethernet/dec/tulip/de4x5.c b/drivers/net/ethernet/dec/tulip/de4x5.c
index cf8b6ff..badff18 100644
--- a/drivers/net/ethernet/dec/tulip/de4x5.c
+++ b/drivers/net/ethernet/dec/tulip/de4x5.c
@@ -995,7 +995,6 @@ static void de4x5_dbg_mii(struct net_device *dev, int k);
static void de4x5_dbg_media(struct net_device *dev);
static void de4x5_dbg_srom(struct de4x5_srom *p);
static void de4x5_dbg_rx(struct sk_buff *skb, int len);
-static int de4x5_strncmp(char *a, char *b, int n);
static int dc21041_infoleaf(struct net_device *dev);
static int dc21140_infoleaf(struct net_device *dev);
static int dc21142_infoleaf(struct net_device *dev);
@@ -4102,8 +4101,7 @@ get_hw_addr(struct net_device *dev)

-** Test for enet addresses in the first 32 bytes. The built-in strncmp
-** didn't seem to work here...?
+** Test for enet addresses in the first 32 bytes.
static int
de4x5_bad_srom(struct de4x5_private *lp)
@@ -4111,8 +4109,8 @@ de4x5_bad_srom(struct de4x5_private *lp)
int i, status = 0;

for (i = 0; i < ARRAY_SIZE(enet_det); i++) {
- if (!de4x5_strncmp((char *)&lp->srom, (char *)&enet_det[i], 3) &&
- !de4x5_strncmp((char *)&lp->srom+0x10, (char *)&enet_det[i], 3)) {
+ if (!memcmp(&lp->srom, &enet_det[i], 3) &&
+ !memcmp((char *)&lp->srom+0x10, &enet_det[i], 3)) {
if (i == 0) {
status = SMC;
} else if (i == 1) {
@@ -4125,18 +4123,6 @@ de4x5_bad_srom(struct de4x5_private *lp)
return status;

-static int
-de4x5_strncmp(char *a, char *b, int n)
- int ret=0;
- for (;n && !ret; n--) {
- ret = *a++ - *b++;
- }
- return ret;
static void
srom_repair(struct net_device *dev, int card)

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