From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH net-next] firewire: net: really fix maximum possible MTU Date: Sat, 29 Oct 2016 23:01:04 -0400 (EDT) Message-ID: <20161029.230104.141605741908542764.davem@davemloft.net> References: <20161023162903.4166a35d@kant> <20161023163056.6bc38610@kant> <20161029221658.03942ff6@kant> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux1394-devel@lists.sourceforge.net, jarod@redhat.com, linux-kernel@vger.kernel.org To: stefanr@s5r6.in-berlin.de Return-path: In-Reply-To: <20161029221658.03942ff6@kant> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Stefan Richter 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 Applied, thanks.