low throughputs with 14e4:4353

francesco.gringoli at ing.unibs.it francesco.gringoli at ing.unibs.it
Wed Nov 30 10:05:25 EST 2011

On Nov 29, 2011, at 10:36 PM, Rafał Miłecki wrote:

> W dniu 29 listopada 2011 21:08 użytkownik Rafał Miłecki
> <zajec5 at gmail.com> napisał:
>> Hey Francesco,
>> W dniu 29 listopada 2011 20:28 użytkownik
>> <francesco.gringoli at ing.unibs.it> napisał:
>>> Hi Rafal,
>>> I bought some 43224 cards to begin playing with the firmware. Unfortunately I have problems with the throughput that is really low. Kernel is the latest from wireless git and firmware comes from broadcom-wl-5.100.138. I see that the transmitted power is low, I monitored it with a spectrum analyzer and it confirmed. A lot of packets are lost given the low power and minstrel always select 1Mb/s. When receiving with the 43224 in monitor mode, I see that it receives only a few of the frames that are received by a close 4318-based box: the reported power levels are low too. Please find attached all info about kernel/firmware and devices below.
>>> I tried all the four cards I have and they behave the same: find a photo of one of them here
>>>        http://www.ing.unibs.it/gringoli/foto.JPG
>>> I tried the cards on a MacBook White, on an Intel Atom based motherboard, Intel Pentium, and AMD Sempron, and I always got very low throughput. The same cards, with the same antennas (everything untouched) but with brcmsmac work well and the spectrum analyzer reports "normal" emitted power levels.
>> I'm fighting with my BCM43224 for last 2 days, I reproduced the
>> problem with poor throughput. I already have some patches but nothing
>> improving situation so far. If I discover anything, I promise to share
>> :)
> After trying some "next" patch while my development, my card started
> working. I've managed to associate and authenticate. I hoped I've
> implemented some lacking part, and found the cure.
> Then I reverted all my patches and... card is still working :( Of
> course I'm doing cold boot for every test.
> I'll give it a rest and will try in next days again.

I found your message on linux-wireless (end of July) reporting that the throughput was about 10Mb/s with bcma. You mention kernel "master-2011-07-26-150-g4ea94a9". I gave it a try (it is a 3.0.0 if I'm not wrong) but I'm still having very low throughput.

Rafal: so you observe good/bad throughputs at random? Sometimes after cold boot it works fine, other times bad?

Did you modprobe using some options?

Many thanks,

> -- 
> Rafał

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