low throughputs with 14e4:4353

[francesco.gringoli at ing.unibs.it]

On Nov 30, 2011, at 10:27 PM, Larry Finger wrote:

> On 11/30/2011 09:05 AM, francesco.gringoli at ing.unibs.it wrote:
>> Larry,
>> 
>> 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?
> 
> My netperf results (3 sec samples) are:
> 
> TCP_MAERTS Test:  13.60 14.41 16.05 15.01 14.70 15.36 14.72 15.07 12.37 11.01
> Results: max 16.05, min 11.01. Mean 14.23(1.44)
> 
> TCP_STREAM Test:   3.00  1.89  1.23  2.12  0.91  1.59  1.46  0.71  1.99  2.12
> Results: max  3.00, min  0.71. Mean  1.70(0.64)
> 
> As you can see, RX is OK, but TX is quite low.
> 
> I will run the same test with brcmsmac later. Their damned Kconfig won't let me build both b43 and brcmsmac at the same time.
Larry, Rafal,

I can now confirm that with kernel 3.0.0-wl everything is ok, tx power is as expected and in fact I achieve up to 23Mb/s (iperf) on free channels. With latest kernel (I'm talking about 3.2.0-rc3-wl) I believe that the initialization of the radio is broken and, in fact, tx power is the lowest possible. I will bisect to check when the problem was introduced.

Cheers,
-Francesco

> 
> Larry
> 
> 
>