[PATCH] mISDN: use memchr_inv

From: Akinobu Mita
Date: Fri Jan 27 2012 - 09:26:00 EST


Use memchr_inv to check if the data contains all same bytes. It is
faster than looping for each byte.

Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Karsten Keil <isdn@xxxxxxxxxxxxxx>
Cc: netdev@xxxxxxxxxxxxxxx
---
drivers/isdn/mISDN/l1oip_core.c | 16 +++-------------
1 files changed, 3 insertions(+), 13 deletions(-)

diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index 22f8ec8..04f115a 100644
--- a/drivers/isdn/mISDN/l1oip_core.c
+++ b/drivers/isdn/mISDN/l1oip_core.c
@@ -1112,7 +1112,7 @@ handle_bmsg(struct mISDNchannel *ch, struct sk_buff *skb)
struct l1oip *hc = bch->hw;
int ret = -EINVAL;
struct mISDNhead *hh = mISDN_HEAD_P(skb);
- int l, ll, i;
+ int l, ll;
unsigned char *p;

switch (hh->prim) {
@@ -1128,13 +1128,8 @@ handle_bmsg(struct mISDNchannel *ch, struct sk_buff *skb)
break;
}
/* check for AIS / ulaw-silence */
- p = skb->data;
l = skb->len;
- for (i = 0; i < l; i++) {
- if (*p++ != 0xff)
- break;
- }
- if (i == l) {
+ if (!memchr_inv(skb->data, 0xff, l)) {
if (debug & DEBUG_L1OIP_MSG)
printk(KERN_DEBUG "%s: got AIS, not sending, "
"but counting\n", __func__);
@@ -1144,13 +1139,8 @@ handle_bmsg(struct mISDNchannel *ch, struct sk_buff *skb)
return 0;
}
/* check for silence */
- p = skb->data;
l = skb->len;
- for (i = 0; i < l; i++) {
- if (*p++ != 0x2a)
- break;
- }
- if (i == l) {
+ if (!memchr_inv(skb->data, 0x2a, l)) {
if (debug & DEBUG_L1OIP_MSG)
printk(KERN_DEBUG "%s: got silence, not sending"
", but counting\n", __func__);
--
1.7.4.4

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