BCM4321 support

Octavian Voicu octavian.voicu at gmail.com
Wed Aug 24 14:32:11 EDT 2011


2011/8/24 Rafał Miłecki <zajec5 at gmail.com>:
> 2011/8/24 Octavian Voicu <octavian.voicu at gmail.com>:
>> The new one is a BCM4321 pcmcia mini-card. It looks identical to [1]
>> (I bought it 2nd hand though): BCM94321MCP3 P3, REV 0A, ver 6.7 r.
>
> What I can see on the photo is mini PCIe card. I didn't hear about any
> recent Broadcom card using PCMCIA slot.

You're right, my bad, I meant PCIe.

>> I got it to work after upgrading to a newer kernel / b43 driver
>> (3.0.3-030003-generic from .deb), but there are a few problems:
>>
>>
>> 1) All networks show as having maximum link quality. Signal level is
>> always 0 dBm.
>>
>> I have many wifi networks around, and most don't have a strong signal.
>> Also, there is no noise level in the iwconfig output:
>>           Link Quality=70/70  Signal level=0 dBm
>>
>> Same goes for iwlist scan. I also tried the Linux STA driver, which
>> correctly shows the link quality (including a Noise level), but for
>> some reason it cannot connect authenticate to my WPA access point
>> (didn't try without encryption).
>>
>> How can I fix this?
>
> Take a look at xmit.c and find the place:
> if ((chanstat & B43_RX_CHAN_PHYTYPE) == B43_PHYTYPE_N) {
> //              s8 rssi = max(rxhdr->power0, rxhdr->power1);
>        //TODO: Find out what the rssi value is (dBm or percentage?)
>        //      and also find out what the maximum possible value is.
>        //      Fill status.ssi and status.signal fields.
> } else {
>
> You need to fix that part, read signal info from RX header.

Thanks, I'll take a look.

>> I also see some invalid misc packets. Any concerns about that?
>
> I didn't hear about that, what exactly is that?

It's from the iwconfig output:

wlan0     IEEE 802.11bg  ESSID:"swn"
...
          Rx invalid nwid:0  Rx invalid crypt:0  Rx invalid frag:0
          Tx excessive retries:0  Invalid misc:53   Missed beacon:0

iwconfig man page says:
       Invalid misc
              Other packets lost in relation with specific wireless operations.

>> Can I use 802.11n with b43?
>
> Not yet, sorry. I'll focus on 802.11n after adding basic support for
> new Broadcom cards.

Fair enough. I don't have an 802.11n AP at the moment anyway.

>> Which firmware do you recommend?
>
> We don't know changelog of the firmware, hopefully using the newest is
> always the best idea. To use firmware 598 or newer you need to use
> very latest wireless tree. I suggest sticking to firmware older than
> 598 for now (like 508).

I switched to 508.154 and seems to be working.

Where is the latest wireless tree? Is it just Linus' vanilla linux.git
tree, or do you have a b43 dev tree?

About sending patches, when I'll have something meaningful, do I send
it to LKML, or here for review?

Octavian



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