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Groups > linux.kernel > #1506711
| From | Stefan Richter <stefanr@s5r6.in-berlin.de> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | [PATCH net-next 2/2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards |
| Date | 2016-10-23 16:40 +0200 |
| Message-ID | <svs6m-2am-11@gated-at.bofh.it> (permalink) |
| References | (2 earlier) <supNg-2j8-41@gated-at.bofh.it> <sv9ZL-7vE-3@gated-at.bofh.it> <sva9r-7yQ-11@gated-at.bofh.it> <svfC9-2Bw-5@gated-at.bofh.it> <svrWF-273-3@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
firewire-net, like the older eth1394 driver, reduced the initial MTU to less than 1500 octets if the local link layer controller's asynchronous packet reception limit was lower. This is bogus, since this reception limit does not have anything to do with the transmission limit. Neither did this reduction affect the TX path positively, nor could it prevent link fragmentation at the RX path. Many FireWire CardBus cards have a max_rec of 9, causing an initial MTU of 1024 - 16 = 1008. RFC 2734 and RFC 3146 allow a minimum max_rec = 8, which would result in an initial MTU of 512 - 16 = 496. On such cards, IPv6 could only be employed if the MTU was manually increased to 1280 or more, i.e. IPv6 would not work without intervention from userland. We now always initialize the MTU to 1500, which is the default according to RFC 2734 and RFC 3146. On a VIA VT6316 based CardBus card which was affected by this, changing the MTU from 1008 to 1500 also increases TX bandwidth by 6 %. RX remains unaffected. CC: netdev@vger.kernel.org CC: linux1394-devel@lists.sourceforge.net CC: Jarod Wilson <jarod@redhat.com> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> --- drivers/firewire/net.c | 8 +------- 1 file changed, 1 insertion(+), 7 deletions(-) diff --git a/drivers/firewire/net.c b/drivers/firewire/net.c index 99379542b263..03715e7d9d92 100644 --- a/drivers/firewire/net.c +++ b/drivers/firewire/net.c @@ -1463,13 +1463,7 @@ static int fwnet_probe(struct fw_unit *unit, goto out; dev->local_fifo = dev->handler.offset; - /* - * Use the RFC 2734 default 1500 octets or the maximum payload - * as initial MTU - */ - net->mtu = min(1500U, - (1U << (card->max_receive + 1)) - - RFC2374_FRAG_HDR_SIZE - IEEE1394_GASP_HDR_SIZE); + net->mtu = 1500U; net->min_mtu = ETH_MIN_MTU; net->max_mtu = ETH_MAX_MTU; -- Stefan Richter -======----- =-=- =-=== http://arcgraph.de/sr/
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[PATCH net-next 0/6] net: use core MTU range checking everywhere Jarod Wilson <jarod@redhat.com> - 2016-10-19 04:40 +0200
[PATCH net-next 6/6] net: use core MTU range checking in misc drivers Jarod Wilson <jarod@redhat.com> - 2016-10-19 04:40 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Robin Holt <robinmholt@gmail.com> - 2016-10-19 16:40 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Sabrina Dubroca <sd@queasysnail.net> - 2016-10-19 18:10 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-20 00:50 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 05:20 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-22 11:40 +0200
Re: [PATCH net-next 6/6] net: use core MTU range checking in misc drivers Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-22 21:00 +0200
Re: [PATCH net-next 0/6] net: use core MTU range checking everywhere David Miller <davem@davemloft.net> - 2016-10-19 21:20 +0200
Re: [PATCH net-next 0/6] net: use core MTU range checking everywhere Jarod Wilson <jarod@redhat.com> - 2016-10-19 21:30 +0200
[PATCH net-next v2 9/9] ipv4/6: use core net MTU range checking Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 3/9] net: use core MTU range checking in wireless drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
Re: [PATCH net-next v2 3/9] net: use core MTU range checking in wireless drivers Johannes Berg <johannes@sipsolutions.net> - 2016-10-20 20:30 +0200
Re: [PATCH net-next v2 3/9] net: use core MTU range checking in wireless drivers David Miller <davem@davemloft.net> - 2016-10-20 20:50 +0200
[PATCH net-next v2 1/9] ethernet: use net core MTU range checking in more drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 4/9] net: use core MTU range checking in WAN drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 2/9] net: use core MTU range checking in USB NIC drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 0/9] net: use core MTU range checking everywhere Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 5/9] net: use core MTU range checking in core net infra Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
RE: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers Haiyang Zhang <haiyangz@microsoft.com> - 2016-10-20 20:10 +0200
RE: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers "Kershner, David A" <David.Kershner@unisys.com> - 2016-10-20 22:50 +0200
Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers "Michael S. Tsirkin" <mst@redhat.com> - 2016-10-20 22:30 +0200
Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers Jarod Wilson <jarod@redhat.com> - 2016-10-21 04:40 +0200
Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers "Michael S. Tsirkin" <mst@redhat.com> - 2016-10-21 05:40 +0200
Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers Aaron Conole <aconole@bytheb.org> - 2016-10-21 15:30 +0200
Re: [PATCH net-next v2 6/9] net: use core MTU range checking in virt drivers Wei Liu <wei.liu2@citrix.com> - 2016-10-21 12:10 +0200
[PATCH net-next v2 8/9] s390/net: use net core MTU range checking Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
[PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Jarod Wilson <jarod@redhat.com> - 2016-10-20 20:00 +0200
Re: [PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Rémi Denis-Courmont <remi@remlab.net> - 2016-10-21 09:00 +0200
Re: [PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Sebastian Reichel <sre@kernel.org> - 2016-10-21 18:30 +0200
Re: [net-next,v2,7/9] net: use core MTU range checking in misc drivers Sven Eckelmann <sven@narfation.org> - 2016-10-22 09:30 +0200
Re: [PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-22 21:20 +0200
Re: [PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-22 21:30 +0200
Re: [PATCH net-next v2 7/9] net: use core MTU range checking in misc drivers Jarod Wilson <jarod@redhat.com> - 2016-10-23 03:20 +0200
[PATCH net-next 1/2] firewire: net: fix maximum possible MTU Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-23 16:30 +0200
[PATCH net-next 2/2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-23 16:40 +0200
Re: [PATCH net-next 2/2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards Jarod Wilson <jarod@redhat.com> - 2016-10-24 04:00 +0200
[PATCH net-next 2/2 v2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards Stefan Richter <stefanr@s5r6.in-berlin.de> - 2016-10-24 14:30 +0200
Re: [PATCH net-next 2/2 v2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards Jarod Wilson <jarod@redhat.com> - 2016-10-25 05:10 +0200
Re: [PATCH net-next 2/2] firewire: net: set initial MTU = 1500 unconditionally, fix IPv6 on some CardBus cards David Miller <davem@davemloft.net> - 2016-10-26 23:40 +0200
Re: [PATCH net-next 1/2] firewire: net: fix maximum possible MTU Jarod Wilson <jarod@redhat.com> - 2016-10-24 04:00 +0200
Re: [PATCH net-next 1/2] firewire: net: fix maximum possible MTU David Miller <davem@davemloft.net> - 2016-10-26 23:40 +0200
Re: [PATCH net-next v2 0/9] net: use core MTU range checking everywhere David Miller <davem@davemloft.net> - 2016-10-20 21:00 +0200
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