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Topic: backfire and b43 driver

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recently I installed backfire 10.03 with kernel 2.6 on my broadcom box which has a bcm4318 wireless device. Because I used brcm2.4 before, so I notice that the performance of wireless is not good as before.
on 2.4 kernel with old driver, I can copy a file through wireless link at 2m/s on my LAN, but now only at 1m/s

my config is:

config 'wifi-device' 'radio0'
        option 'type' 'mac80211'
        option 'macaddr' '00:14:a5:1b:d9:a8'
        option 'hwmode' '11g'
        option 'disabled' '0'
        option 'channel' '6'

config 'wifi-iface'
        option 'device' 'radio0'
        option 'network' 'lan'
        option 'mode' 'ap'
        option 'ssid' 'OpenWrt-XXX'
        option 'encryption' 'psk2'
        option 'key' 'xxxxx'
        option 'hidden' '1'

is there something wrong with my config? When my laptop connect to the wireless, it appears that it is a 48m network, not 54m

thanks~

(Last edited by hayate on 10 Apr 2010, 11:02)

I am using Backfire rc2 on my Asus WL500gP, and I am also experiencing the same performance drop. The reason is most probably the b43 driver. Take a look at this site:

http://wireless.kernel.org/en/users/Drivers/b43

Here they say that BCM 4318 is _not_ working in AP mode due to some spurious packet loss issues. Besides the performance drop, sometimes my client cannot connect to the AP (authentication is WPA-Enterprise), and the only solution is wifi down && wifi up. Stupid Broadcom chips... sad

grogi wrote:

You say you have broadcom radio, but config file mentions mac80211...

It is automatically configured by the install, I do have a bcm4318 radio.

And as I know, don't the mac80211 drivers include the b43 driver?

If I'm wrong please correct me.

neutron wrote:

I am using Backfire rc2 on my Asus WL500gP, and I am also experiencing the same performance drop. The reason is most probably the b43 driver. Take a look at this site:

http://wireless.kernel.org/en/users/Drivers/b43

Here they say that BCM 4318 is _not_ working in AP mode due to some spurious packet loss issues. Besides the performance drop, sometimes my client cannot connect to the AP (authentication is WPA-Enterprise), and the only solution is wifi down && wifi up. Stupid Broadcom chips... sad

Thanks for your information.
But I remember that backfire release said that now broadcom wireless is working

Just tried the final release and it doesn't seem to bring up the wireless interface on a WBR2-G54, is it necessary to install the kmod-b43 manually...?

Was using http://downloads.openwrt.org/backfire/1 … uashfs.trx

Thanks in advance.

(Last edited by loyukfai on 10 Apr 2010, 19:28)

Please paste the generated wireless config

hah!  new discovery. When I change my wifi card to atheros 5212, the performance become worse!
I found that if I use no Encryption (currently wpa2-psk), the performance is good

And it seems there are many similar issues around forum

(Last edited by hayate on 11 Apr 2010, 09:01)

hayate wrote:
neutron wrote:

Here they say that BCM 4318 is _not_ working in AP mode due to some spurious packet loss issues. Besides the performance drop, sometimes my client cannot connect to the AP (authentication is WPA-Enterprise), and the only solution is wifi down && wifi up. Stupid Broadcom chips... sad

Thanks for your information.
But I remember that backfire release said that now broadcom wireless is working

b43 in Backfire works on most BCM4306-BCM4318-based cards, included master (AP) mode. Unfortunately there are some models of BCM4318 which suffer from transmission problems and are unstable as a result, mostly noticeably when running as AP. Others models of BCM4318 seems to run fine.
Older BCM4306-based cards don't suffer from these problems and run great with b43.

And on some models (e.g. Asus WL500gP v2) it doesn't work at all. :-(

b43 driver is unstable in my WRT54GL, it automatically disconnect and can't get it connected unless reboot after several hours. WRT54GL uses BCM4320.

AdeBe wrote:

And on some models (e.g. Asus WL500gP v2) it doesn't work at all. :-(

The v2 uses a BCM4312 with a LP phy, it's still experimental (and probably unreliable) but should work with recent mac80211 versions. Not sure if the one included in Backtrack is recent enough, though.

helloworld1 wrote:

b43 driver is unstable in my WRT54GL, it automatically disconnect and can't get it connected unless reboot after several hours. WRT54GL uses BCM4320.

There are different core revision of BCM4320 around.
Can you (and everyone else who has problems with b43 in Backfire) please post the output of

dmesg | grep "WLAN found"

Is this one useful?
WRT54GL v1.1
# dmesg | grep wl0
wl0: wlc_attach: chiprev 0 coreunit 0 corerev 9 cccap 0x4787aa maccap 0x0 band 2.4G, phy_type 2 phy_rev 7 ana_rev 2
wl0: Broadcom BCM4320 802.11 Wireless Controller 4.150.10.5

More info from /proc/pci

  Bus  0, device   5, function  0:
    Class 0280: PCI device 14e4:4320 (rev 0).
      IRQ 2.
      Master Capable.  Latency=64. 
      Non-prefetchable 32 bit memory at 0x18005000 [0x18005fff].

(Last edited by helloworld1 on 11 Apr 2010, 05:15)

those of you who have performance drop with the backfire may read this ticket https://dev.openwrt.org/ticket/7064.

It's for atheros drivers actually but I believe b43 is also affected

to test add country code text field on your wireless configuration page and put 392 there. Save&Apply and reboot. Yes reboot is necessary. Share your experience.

Well, the country code trick does not work for me, because I cannot add such a field to the configuration. The only selectable fields are Fragmentation threshold and RTS/CTS threshold. My WLAN chip revision is:

root@OpenWrt:~# dmesg | grep "WLAN found"
b43-phy0: Broadcom 4318 WLAN found (core revision 9)

my experience is when I use ath5k and wpa2-psk the performance is very bad and cpu is 100%, if I use madwifi, all is OK, the throughput can reach 3MB/s
When using ath5k and NO encryption, the effect is acceptable.


ps: sorry for involving ath driver here, because I have both broadcom and atheros card.

(Last edited by hayate on 12 Apr 2010, 13:08)

The throughput of my WRT54GL 1.1 is 13Mb/s for b43 and 16Mb/s for wl. The speed is very good but the problem is stability.
The wired one is 39.9 Mb/s.

(Last edited by helloworld1 on 12 Apr 2010, 05:28)

helloworld1 wrote:

The throughput of my WRT54GL 1.1 is 13Mb/s for b43 and 16Mb/s for wl. The speed is very good but the problem is stability.

That's a corerev 9, then... I know the OpenFWWF researchers use several WRT54GL corerev 9 with b43 and they seem to find them stable. They don't use encryption though. Does it make a difference in your case?
I'll ask them later about what exact kernel and mac80211 version they're using.

loyukfai wrote:

Just tried the final release and it doesn't seem to bring up the wireless interface on a WBR2-G54, is it necessary to install the kmod-b43 manually...?

Was using http://downloads.openwrt.org/backfire/1 … uashfs.trx

Thanks in advance.

Turns out that the problem is because I set the wireless channel to "auto", now I set it as "5" and it works.

Cheers.

loyukfai wrote:
loyukfai wrote:

Just tried the final release and it doesn't seem to bring up the wireless interface on a WBR2-G54, is it necessary to install the kmod-b43 manually...?

Was using http://downloads.openwrt.org/backfire/1 … uashfs.trx

Thanks in advance.

Turns out that the problem is because I set the wireless channel to "auto", now I set it as "5" and it works.

Cheers.

The stability issue has nothing to do with this though.

helloworld1 wrote:

The stability issue has nothing to do with this though.

I use WPA/WPA2-PSK, it's been stable, so far. I haven't thoroughly tested the speed yet through.

Cheers.

(Last edited by loyukfai on 16 Apr 2010, 17:05)

With my WRTSL54GS I got 800 kB/s with b43 (otherwise stable). went back to brcm-2.4 that gives me 2 MB/s.
(that's copying from a USB disk attached to the router)

(Last edited by attila123456 on 16 Apr 2010, 17:23)

attila123456 wrote:

(that's copying from a USB disk attached to the router)

Note that on these (CPU-limited) routers sending packets from the router itself (as in copying from USB) is usually slower than routing/bridging (ethernet <-> wireless). The b43 driver probably has more overhead in that situation than the binary driver. If you can, try again moving some files between the ethernet ports and the wireless.

Have somebody tried to test wifi performance with any of the new release candidates ( Backfire 10.03.1-rcX ) ?

I'd like to ask the above mentioned question again: what is the current performance of b43 driver, using Backfire 10.3.1-rc or trunk version?

Using Backfire 10.03.1-rc3 and BCM4318 WLAN I experience lockups in 802.11g mode. In 802.11b mode the speed is about 650 kbytes/s (with WPA2)

(Last edited by blondquirk on 22 Nov 2010, 23:36)