From 4adf7bf7bbaefe71133305193c25d32863115dda Mon Sep 17 00:00:00 2001
From: Stefan Richter <stefanr@s5r6.in-berlin.de>
Date: Wed, 2 Nov 2016 21:09:44 +0100
Subject: [PATCH] firewire: net: max MTU off by one
Git-commit: 4adf7bf7bbaefe71133305193c25d32863115dda
Patch-mainline: v4.16-rc1
References: bsc#1051510
The latest max_mtu patch missed that datagram_size is actually one less
than the datagram's Total Length.
Fixes: 357f4aae859b ("firewire: net: really fix maximum possible MTU")
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/firewire/net.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c
index 242359c2d1f1..60e75e6d9104 100644
--- a/drivers/firewire/net.c
+++ b/drivers/firewire/net.c
@@ -1480,9 +1480,14 @@ static int fwnet_probe(struct fw_unit *unit,
goto out;
dev->local_fifo = dev->handler.offset;
+ /*
+ * default MTU: RFC 2734 cl. 4, RFC 3146 cl. 4
+ * maximum MTU: RFC 2734 cl. 4.2, fragment encapsulation header's
+ * maximum possible datagram_size + 1 = 0xfff + 1
+ */
net->mtu = 1500U;
net->min_mtu = ETH_MIN_MTU;
- net->max_mtu = 0xfff;
+ net->max_mtu = 4096U;
/* Set our hardware address while we're at it */
ha = (union fwnet_hwaddr *)net->dev_addr;
--
2.18.0