2004-03-04 18:02:20

by Thomas Mueller

[permalink] [raw]
Subject: 2.6 much worse than 2.4 on poor wlan reception

Hi,

I have big problems with kernel 2.6 and WLAN. Quite often the connection
interrupts completely, I can't transfer anything for minutes - making
2.6 unusable for me :-(
I'm only about 5 meters away from my AP, but unfortunately there's a
celeiling between me and the AP to the reception is poor.

My hardware is a SMC 2632 PCMCIA card (802.11b) in a IBM Thinkpad A30
and a SMC AP.

lspci:
02:00.0 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev 80)
02:00.1 CardBus bridge: Ricoh Co Ltd RL5c476 II (rev 80)

blade:~# cardctl ident
Socket 0:
no product info available
Socket 1:
product info: "SMC", "SMC2632W", "Version 01.02", ""
manfid: 0x0156, 0x0002
function: 6 (network)

The wireless-tools have version 26+27pre10-3, pcmcia-cs has 3.2.5, both
from Debian Sid. I have tried kernels 2.6.0, .1 and .2.
Every kernel 2.4 I've had running until now worked very well.

-----------------------------------------------------------
2.4.20:

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
Rx invalid nwid:0 Rx invalid crypt:661 Rx invalid frag:0
Tx excessive retries:2751 Invalid misc:0 Missed beacon:0

lsmod:
orinoco_cs 4776 1
orinoco 32068 0 [orinoco_cs]
hermes 6244 0 [orinoco_cs orinoco]
ds 7060 2 [orinoco_cs]
yenta_socket 10080 2
pcmcia_core 44928 0 [orinoco_cs ds yenta_socket]

tmm@blade:~$ netio -u 10.0.0.15
NETIO - Network Throughput Benchmark, Version 1.21
(C) 1997-2003 Kai Uwe Rommel

UDP connection established.
Packet size 1k bytes: 557 KByte/s (0%) Tx, 261 KByte/s (73%) Rx.
Packet size 2k bytes: 553 KByte/s (0%) Tx, 89 KByte/s (90%) Rx.
Packet size 4k bytes: 626 KByte/s (0%) Tx, 61444 Byte/s (92%) Rx.
Packet size 8k bytes: 517 KByte/s (2%) Tx, 13393 Byte/s (98%) Rx.
Packet size 16k bytes: 565 KByte/s (3%) Tx, 10924 Byte/s (98%) Rx.
Packet size 32k bytes: 565 KByte/s (3%) Tx, 13787 Byte/s (98%) Rx.
Done.

-----------------------------------------------------------
2.6.2:

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
Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0
Tx excessive retries:0 Invalid misc:0 Missed beacon:0

orinoco_cs 9192 1
orinoco 43980 1 orinoco_cs
hermes 8512 2 orinoco_cs,orinoco
ds 15940 5 orinoco_cs
i82365 20876 1
pcmcia_core 71456 3 orinoco_cs,ds,i82365

tmm@blade:~$ netio -u 10.0.0.15

NETIO - Network Throughput Benchmark, Version 1.21
(C) 1997-2003 Kai Uwe Rommel

UDP connection established.
Packet size 1k bytes: 289 KByte/s (99%) Tx, 223 KByte/s (75%) Rx.
Packet size 2k bytes: 0 Byte/s (100%) Tx, 21 KByte/s (91%) Rx.
Packet size 4k bytes: 440 KByte/s (99%) Tx, 61333 Byte/s (94%) Rx.
Packet size 8k bytes: 382 KByte/s (96%) Tx, 14438 Byte/s (98%) Rx.
Packet size 16k bytes: 369 KByte/s (96%) Tx, 2365 Byte/s (98%) Rx.
Packet size 32k bytes: 239 KByte/s (98%) Tx, 3005 Byte/s (98%) Rx.
Done.

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.

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

Thanks a lot!


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


2004-03-04 21:57:37

by Denis Vlasenko

[permalink] [raw]
Subject: Re: 2.6 much worse than 2.4 on poor wlan reception

On Thursday 04 March 2004 20:01, Thomas Mueller wrote:
> I have big problems with kernel 2.6 and WLAN. Quite often the connection
> interrupts completely, I can't transfer anything for minutes - making
> 2.6 unusable for me :-(

> 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).

Let's see how much errors do you have. Do this:

# cat /proc/net/wireless /proc/net/dev

On my system wlan1 has "Link Quality:66/92"
(wlan0 is an AP, has no meaningful Link Quality)

Inter-| sta-| Quality | Discarded packets | Missed | WE
face | tus | link level noise | nwid crypt frag retry misc | beacon | 16
wlan0: 0000 0 0 0 0 9178 13 23727 142280 0
wlan1: 0000 66. 195. 156. 0 0 0 3422 309008 0

Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
wlan0:1829928225 2539552 0 80689 0 0 0 0 1966341385 2579089 0 42 0 0 0 0
wlan1:143242367 907236 0 0 0 0 0 0 11481487 74357 0 0 0 0 0 0

So, wlan1: 907236 rx packets, 3422 retries
(and 309008 packets wasn't for me, wrong MAC, I suppose ;) )
What's your numbers?

> 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?

> 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?
--
vda

2004-03-05 09:23:08

by Jes Sorensen

[permalink] [raw]
Subject: Re: 2.6 much worse than 2.4 on poor wlan reception

>>>>> "Thomas" == Thomas Mueller <[email protected]> writes:

Thomas> Kernel 2.4 works far better in the poor reception situation I
Thomas> have, anyone any idea what I could do without moving the AP or
Thomas> laptop? When I'm near my AP everything works fine with 2.6
Thomas> too.

Start out by forcing it to a lower link speed, at that signal quality
you really don't want to try and go above 2MBit/sec. If you keep
trying to do 11MBit/sec the card will constantly try the higher rate
and then lose signal, drop down and try again. Fixing the rate should
improve the situation - at least it has always done so for me ;-)

Cheers,
Jes

2004-03-07 11:33:31

by Thomas Mueller

[permalink] [raw]
Subject: Re: 2.6 much worse than 2.4 on poor wlan reception

Hi Jes,

Jes Sorensen meinte am Friday, dem 05. March 2004:

> Thomas> Kernel 2.4 works far better in the poor reception situation I
> Thomas> have, anyone any idea what I could do without moving the AP or
> Thomas> laptop? When I'm near my AP everything works fine with 2.6
> Thomas> too.
>
> Start out by forcing it to a lower link speed, at that signal quality
> you really don't want to try and go above 2MBit/sec. If you keep
> trying to do 11MBit/sec the card will constantly try the higher rate
> and then lose signal, drop down and try again. Fixing the rate should
> improve the situation - at least it has always done so for me ;-)

I tried that (rate 2M auto) but that doesn't improve anything. I still
loose the connection to the AP, I don't think that happens less frequent
than at 11 MBit/s.


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

2004-03-07 12:02:00

by Thomas Mueller

[permalink] [raw]
Subject: Re: 2.6 much worse than 2.4 on poor wlan reception

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)