Re: 2.6 much worse than 2.4 on poor wlan reception

From: Thomas Mueller
Date: Sun Mar 07 2004 - 07:03:44 EST


Hi Denis,

> > blade:~# iwconfig eth1
> > eth1 IEEE 802.11-DS ESSID:"WLAN" Nickname:"Prism I"
> > Mode:Managed Frequency:2.412GHz Access Point:00:60:B3:17:F8:8C
> > Bit Rate:11Mb/s Tx-Power=15 dBm Sensitivity:1/3
> > Retry min limit:8 RTS thr:off Fragment thr:off
> > Encryption key:[ secret ] Security mode:open
> > Power Management:off
> > Link Quality:1/92 Signal level:-101 dBm Noise level:-149 dBm
>
> I have Prism 2.5 cards. I run them with hostap driver.
> Link quality of 1/92 is very bad. You are on the edge
> of losing connection. (At least this is the case for
> my hardware).

Yes I am. When I move some meters in the room I loose connection with
kernel 2.4 too.

> Let's see how much errors do you have. Do this:
>
> # cat /proc/net/wireless /proc/net/dev
[..]

tmm@blade:~$ cat /proc/net/wireless /proc/net/dev
Inter-| sta-| Quality | Discarded packets |
Missed | WE
face | tus | link level noise | nwid crypt frag retry misc |
beacon | 16
eth1: 0000 0. 150. 107. 0 8 0 0 0
0
Inter-| Receive |
Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes
packets errs drop fifo colls carrier compressed
lo: 58298 881 0 0 0 0 0 0
58298 881 0 0 0 0 0 0
eth0: 0 0 0 0 0 0 0 0
3456 14 0 0 0 0 0 0
eth1: 532101 1336 0 0 0 0 0 0
223614 1299 466 0 0 0 0 0
sit0: 0 0 0 0 0 0 0 0
0 0 0 0 0 0 0 0

That's really interesting, thanks for that hint!
Transmit: 1299 packets, 466 errs - argh.

When I can't transmit anything 'errs' increases by one every few
seconds.

As comparison: kernel 2.4.20 has 1743 packets and 9 errs at the moment.
So the interesting question is: why is the error rate with kernel 2.6
that high?

> > There was a break when netio transfered the 2k blocks.
> >
> > My log is full of entries like this one:
> > Mar 1 17:54:12 blade kernel: eth1: New link status: AP Out of Range
> > (0004)
> > Mar 1 17:54:12 blade kernel: eth1: New link status: AP In Range (0005)
> > Mar 1 17:54:16 blade kernel: eth1: New link status: AP Out of Range
> > (0004)
> > Mar 1 17:54:16 blade kernel: eth1: New link status: AP In Range (0005)
> > Mar 1 17:54:19 blade kernel: eth1: New link status: AP Out of Range
> > (0004)
> > Mar 1 17:54:20 blade kernel: eth1: New link status: AP In Range (0005)
> > Mar 1 17:54:22 blade kernel: eth1: New link status: AP Out of Range
> > (0004)
> >
> > Kernel 2.4 works far better in the poor reception situation I have,
> > anyone any idea what I could do without moving the AP or laptop?
> > When I'm near my AP everything works fine with 2.6 too.
>
> Is your orinoco driver is the same for 2.4 and 2.6?
> Maybe 2.6 one has a bit lower max retry count or some such?

2.6.2 has version 0.13e, 2.4.23 has 0.13d. I diffed the orinoco.* but
there are only small changes.

> > BTW: removing the PCMCIA card when it's in use freezes my system
> > completely, that was no problem with 2.4.
>
> No oops? No SysRq?

Nope, it just freezes :-(


--
MfG Thomas Mueller - http://www.tmueller.com for pgp key (95702B3B)
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