| Message ID | 20161029221658.03942ff6@kant |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Stefan Richter <stefanr@s5r6.in-berlin.de> Date: Sat, 29 Oct 2016 22:16:58 +0200 > The maximum unicast datagram size /without/ link fragmentation is > 4096 - 4 = 4092 (max IEEE 1394 async payload size at >= S800 bus speed, > minus unfragmented encapssulation header). Max broadcast datagram size > without fragmentation is 8 bytes less than that (due to GASP header). > > The maximum datagram size /with/ link fragmentation is 0xfff = 4095 > for unicast and broadcast. This is because the RFC 2734 fragment > encapsulation header field for datagram size is only 12 bits wide. > > Fixes: 5d48f00d836a('firewire: net: fix maximum possible MTU') > Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Applied, thanks.
diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index 03715e7d9d92..363fc5ec1a4e 100644 --- a/drivers/firewire/net.c +++ b/drivers/firewire/net.c @@ -1465,7 +1465,7 @@ static int fwnet_probe(struct fw_unit *unit, net->mtu = 1500U; net->min_mtu = ETH_MIN_MTU; - net->max_mtu = ETH_MAX_MTU; + net->max_mtu = 0xfff; /* Set our hardware address while we're at it */ ha = (union fwnet_hwaddr *)net->dev_addr;
The maximum unicast datagram size /without/ link fragmentation is 4096 - 4 = 4092 (max IEEE 1394 async payload size at >= S800 bus speed, minus unfragmented encapssulation header). Max broadcast datagram size without fragmentation is 8 bytes less than that (due to GASP header). The maximum datagram size /with/ link fragmentation is 0xfff = 4095 for unicast and broadcast. This is because the RFC 2734 fragment encapsulation header field for datagram size is only 12 bits wide. Fixes: 5d48f00d836a('firewire: net: fix maximum possible MTU') Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> --- drivers/firewire/net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)