Subject: Re: CVS commit: src/sys/net
To: YAMAMOTO Takashi <yamt@mwd.biglobe.ne.jp>
From: Jaromir Dolecek <jdolecek@NetBSD.org>
List: tech-net
Date: 06/12/2005 17:20:17
On Sun, Jun 12, 2005 at 09:40:45PM +0900, YAMAMOTO Takashi wrote:
> actually PACKET_TAG_VLAN contains whole TCI including priority
> at least for received packets from some drivers.
> you changed only transmit side not to include priority.
> i don't think it's a good idea.

AFAIK all the drivers which use HW tagging have stripped the priority
on transmit & receive side even before introduction of VLAN_TAG_VALUE().

We only use/set the VLAN ID part of the tag and thus the extra bits
don't hold any information we want to keep, for either transmit
or receive side.

It shouldn't matter either way (the heigh bits shouldn't be set for
transmit and should be ignored on receive). I think it's safer
practice to mask the bits we don't use off, until we start
using/setting them. So I think it's better to keep the current way.

Jaromir
-- 
Jaromir Dolecek <jdolecek@NetBSD.org>            http://www.NetBSD.cz/
-=- We can walk our road together if our goals are all the same;     -=-
-=- We can run alone and free if we pursue a different aim.          -=-