[PATCH] zd1211rw: Optimized handling of zero length entries in length info

There are a high number of split USB transactions, which contain
only one packet but have a length info field. This patch optimizes
this code by stopping parsing the length info structure if a zero
length field is encountered.

Signed-off-by: Ulrich Kunitz <kune@deine-taler.de>
Signed-off-by: Daniel Drake <dsd@gentoo.org>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/net/wireless/zd1211rw/zd_usb.c b/drivers/net/wireless/zd1211rw/zd_usb.c
index c3449cfae7e8..aa782e88754b 100644
--- a/drivers/net/wireless/zd1211rw/zd_usb.c
+++ b/drivers/net/wireless/zd1211rw/zd_usb.c
@@ -593,6 +593,8 @@ static void handle_rx_packet(struct zd_usb *usb, const u8 *buffer,
                 unsigned int l, k, n;
                 for (i = 0, l = 0;; i++) {
                         k = le16_to_cpu(get_unaligned(&length_info->length[i]));
+                        if (k == 0)
+                                return;
                         n = l+k;
                         if (n > length)
                                 return;