mISDN: use memchr_inv

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@gmail.com>
Cc: Karsten Keil <isdn@linux-pingi.de>
Cc: netdev@vger.kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 13 deletions

diff --git a/drivers/isdn/mISDN/l1oip_core.c b/drivers/isdn/mISDN/l1oip_core.c
index 22f8ec8b9247..04f115a9c43e 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__);