From: Mike Sinkovsky <msink@permonline•ru>
To: David Miller <davem@davemloft•net>
Cc: netdev@vger•kernel.org
Subject: Re: [PATCH v4] Ethernet driver for the WIZnet W5300 chip
Date: Wed, 28 Mar 2012 11:52:43 +0600 [thread overview]
Message-ID: <4F72A72B.5020609@permonline.ru> (raw)
In-Reply-To: <20120327.223545.1996930432677091672.davem@davemloft.net>
28.03.2012 8:35, David Miller wrote:
>> +/*
>> + * Frame size is hardwired to 1514 bytes (including header),
>> + * => MTU for 802.1Q frames must be set to 1500-4 = 1496
>> + */
>> +#define W5300_HARD_MTU 1500
>
> I've told you that you must set the VLAN challenged feature flag
> (NETIF_F_VLAN_CHALLENGED) for devices which have this restriction.
>
> Just set that, and remove this comment, since the feature bit setting
> documents this restriction fully and perfectly.
From Documentation/netdev-features.txt:
>NETIF_F_VLAN_CHALLENGED should be set for devices which can't cope
with VLAN
>headers. Some drivers set this because the cards can't handle the
bigger MTU.
>[FIXME: Those cases could be fixed in VLAN code by allowing only
reduced-MTU
>VLANs. This may be not useful, though.]
My case is exactly what is here in FIXME comment - yes, this chip cannot
handle full size MTU for VLANs, and TCP/IP traffic don't work well over
this VLAN. But we actually use it for traffic where frame size is known
to be less than 1500 - TDMoE to Asterisk in our case - and it works
perfectly.
So as ideal we'll like to disable TCP/IP over this sort of VLANs, but
still enable TDMoE traffic. If it is possible.
But if you want - ok, I'll disable VLAN support entirely for this chip
in mainline version.
(Now working on similar driver for W5100 chip, hopefully will post both
soon.)
--
Mike
next prev parent reply other threads:[~2012-03-28 5:52 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-03-19 9:23 [PATCH v2] ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-03-20 18:08 ` Ben Hutchings
2012-03-21 6:20 ` Mike Sinkovsky
2012-03-22 16:57 ` Ben Hutchings
2012-03-21 14:49 ` Florian Fainelli
2012-03-22 6:58 ` Mike Sinkovsky
2012-03-24 11:02 ` [PATCH v3] Ethernet " Mike Sinkovsky
2012-03-24 15:53 ` Joe Perches
2012-03-24 16:10 ` Eric Dumazet
2012-03-26 9:05 ` Mike Sinkovsky
2012-03-26 9:07 ` [PATCH v4] " Mike Sinkovsky
2012-03-28 2:35 ` David Miller
2012-03-28 5:52 ` Mike Sinkovsky [this message]
2012-03-28 6:22 ` David Miller
2012-03-30 7:00 ` [PATCH v5 1/2] " Mike Sinkovsky
2012-03-31 21:45 ` Mark Brown
2012-03-30 7:00 ` [PATCH v5 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-03-30 9:23 ` Eric Dumazet
2012-03-31 9:40 ` Francois Romieu
2012-03-31 9:46 ` Francois Romieu
2012-03-31 9:52 ` Mike Sinkovsky
2012-03-31 10:24 ` Eric Dumazet
2012-03-31 21:23 ` Mark Brown
2012-04-02 9:40 ` Mike Sinkovsky
2012-04-02 11:21 ` Mark Brown
2012-04-03 10:58 ` [PATCH v6 0/2] Ethernet drivers for WIZnet chips Mike Sinkovsky
2012-04-03 11:39 ` Eric Dumazet
2012-04-03 12:15 ` Mike Sinkovsky
2012-04-03 12:29 ` Eric Dumazet
2012-04-04 5:58 ` Mike Sinkovsky
2012-04-04 6:17 ` Eric Dumazet
2012-04-04 7:25 ` Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 " Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 " Mike Sinkovsky
2012-04-05 1:15 ` David Miller
2012-04-05 5:36 ` Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 11:57 ` [PATCH v8 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 0/2] Ethernet drivers for WIZnet chips Mike Sinkovsky
2012-04-05 5:33 ` [PATCH v9 " Mike Sinkovsky
2012-04-05 5:47 ` David Miller
2012-04-05 5:33 ` [PATCH v9 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-05 5:33 ` [PATCH v9 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 12:08 ` [PATCH v8 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-04 7:23 ` [PATCH v7 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
2012-04-03 10:58 ` [PATCH v6 1/2] Ethernet driver for the WIZnet W5300 chip Mike Sinkovsky
2012-04-03 13:36 ` Mark Brown
2012-04-04 6:18 ` Mike Sinkovsky
2012-04-04 10:01 ` Mark Brown
2012-04-04 11:00 ` Mike Sinkovsky
2012-04-03 10:58 ` [PATCH v6 2/2] Ethernet driver for the WIZnet W5100 chip Mike Sinkovsky
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