[PATCH] myri10ge: fix big_bytes in case of vlan frames

Fix sizing of big_bytes in the case of vlan frames. The 4
VLAN_HLEN bytes were omitted, leading to sizing the big buffer
4 bytes smaller than it should be.  Due to how rx buffers are
carved from pages, this was harmless for the common (9000, 1500)
byte MTUs, but could lead to data corruption for some MTUs.

Signed-off-by: Brice Goglin <brice@myri.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>

diff --git a/drivers/net/myri10ge/myri10ge.c b/drivers/net/myri10ge/myri10ge.c
index d38217a..a0d1dae 100644 (file)
--- a/drivers/net/myri10ge/myri10ge.c
+++ b/drivers/net/myri10ge/myri10ge.c
@@ -1696,11 +1696,11 @@ static int myri10ge_open(struct net_device *dev)
         * tell him the buffer is larger, because we only use 1
         * buffer/pkt, and the mtu will prevent overruns.
         */
-       big_pow2 = dev->mtu + ETH_HLEN + MXGEFW_PAD;
+       big_pow2 = dev->mtu + ETH_HLEN + VLAN_HLEN + MXGEFW_PAD;
        if (big_pow2 < MYRI10GE_ALLOC_SIZE / 2) {
                while ((big_pow2 & (big_pow2 - 1)) != 0)
                        big_pow2++;
-               mgp->big_bytes = dev->mtu + ETH_HLEN + MXGEFW_PAD;
+               mgp->big_bytes = dev->mtu + ETH_HLEN + VLAN_HLEN + MXGEFW_PAD;
        } else {
                big_pow2 = MYRI10GE_ALLOC_SIZE;
                mgp->big_bytes = big_pow2;