Subject: Re: ural(4) for NetBSD 3.0, now sync'ed with OpenBSD ural driver
To: None <tech-net@NetBSD.org, tech-kern@NetBSD.org>
From: David Young <email@example.com>
Date: 11/26/2005 16:06:04
On Sat, Nov 26, 2005 at 10:29:32PM +0100, iMil wrote:
> -----BEGIN PGP SIGNED MESSAGE-----
> Hash: SHA1
> following Damien Bergamini's advice (the original author of the ral(4)
> driver), i've synchronized yesterday's ural(4) backport with current
> OpenBSD driver. Follow the same procedure i've given yesterday to compile
> it. I kept yesterday's archive untouched, you'll find the new driver at
> Damien's recent commits fixes some TX issues and add a rate control
> algorithm for BSS mode (AMRR).
AMRR is already in the NetBSD tree, although it is coupled with ath(4);
see src/sys/dev/ic/athrate-amrr.[ch]. I prefer that the code isn't
duplicated in ural(4).
BTW, it would be enormously helpful to make the ath(4) bitrate-selection
algorithms in dev/ic/athrate-* generic, so that drivers such as atw,
ral, rtw can also benefit.
As far as bitrate-selection algorithms go, AMRR seems naive to me.
I made SampleRate (athrate-sample.[ch]) the default for ath(4), since it
is based on experimental results from 802.11 testbeds. Alas, SampleRate
may be buggy. I understand there are newer versions of SampleRate
somewhere on the Internet; they may fix the bugs.
AMRR is a perplexing choice for ural(4). AMRR stands for "Adaptive
Multi-Rate Retry." AFAICT, the ural(4) hardware does not even support
multi-rate retry. Maybe I have overlooked something.
> - -------------------------
> iMil <firstname.lastname@example.org> _
> http://gcu-squad.org ASCII ribbon campaign ( )
> - against HTML email X
> & vCards / \
> -----BEGIN PGP SIGNATURE-----
> Version: GnuPG v1.4.1 (NetBSD)
> -----END PGP SIGNATURE-----
David Young OJC Technologies
email@example.com Urbana, IL * (217) 278-3933