From: Divy Le Ray <divy@chelsio.com>
Date: Sat, 13 Feb 2010 09:44:30 +0000 (+0000)
Subject: cxgb3: FIx VLAN over Jumbo frames
X-Git-Tag: v2.6.34-rc1~233^2~314
X-Git-Url: http://ftp.safe.ca/?p=safe%2Fjmp%2Flinux-2.6;a=commitdiff_plain;h=38a8fc0fcf86f131f8bddf3787f9dfa7325bd981

cxgb3: FIx VLAN over Jumbo frames

The mac is expected to auto-inflate the Maximum Frame size for VLAN
tagged frames. It however does not work with jumbo frames.
Work around the bug adding 4 to the Maximum Frame for MTUs
greater than 1536.

Signed-off-by: Divy Le Ray <divy@chelsio.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/net/cxgb3/xgmac.c b/drivers/net/cxgb3/xgmac.c
index 0109ee4..0c08de5 100644
--- a/drivers/net/cxgb3/xgmac.c
+++ b/drivers/net/cxgb3/xgmac.c
@@ -353,6 +353,9 @@ int t3_mac_set_mtu(struct cmac *mac, unsigned int mtu)
 	 * packet size register includes header, but not FCS.
 	 */
 	mtu += 14;
+	if (mtu > 1536)
+		mtu += 4;
+
 	if (mtu > MAX_FRAME_SIZE - 4)
 		return -EINVAL;
 	t3_write_reg(adap, A_XGM_RX_MAX_PKT_SIZE + mac->offset, mtu);