Incoerency in iw (or mac80211 or drivers) behavior

Incoerency in iw (or mac80211 or drivers) behavior

[Danilo]

Hello,
I figured out that the command: 

iw dev wlan0 set bitrates legacy-5 24

has different behaviors in different devices.

With iwl3945 wireless cards, it fixes the rate at 24Mbps ALSO for multicast 
frames while in iwl4965 cards, it doesn't.


In both cases I tried with ubuntu linux 12.04 and kernel-3.2.0-32-generic using  
iwl4965/iwl_legacy driver for 4965 and iwl3945/iwl_legacy driver for 3945.


I've also tried with compat-wireless-3.6, same result.

What's the expected behavior? 

Thanks in advance,
 D. Tardioli

Re: Incoherency in iw (or mac80211 or drivers) behavior -- possible BUG in iwl4965

[Danilo]

Danilo <dantard@...> writes:

> 
> Hello,
> I figured out that the command: 
> 
> iw dev wlan0 set bitrates legacy-5 24
> 
> has different behaviors in different devices.
> 
> With iwl3945 wireless cards, it fixes the rate at 24Mbps ALSO for multicast 
> frames while in iwl4965 cards, it doesn't.
> 
> In both cases I tried with ubuntu linux 12.04 and kernel-3.2.0-32-generic 
using  
> iwl4965/iwl_legacy driver for 4965 and iwl3945/iwl_legacy driver for 3945.
> 
> I've also tried with compat-wireless-3.6, same result.
> 
> What's the expected behavior? 
> 
> Thanks in advance,
>  D. Tardioli
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
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> 
> 

Hello,
I answer myself:
I've tried with ath5k-compatible card and it behaves like iwl3945.
It means that when fixed the bitrates with a single value, the card always use 
that bitrate ALSO for broadcast frames.

The iwl4965 doesn't behave this way.
Any suggestion on how to solve the problem?

Regards.

Re: Incoherency in iw (or mac80211 or drivers) behavior -- possible BUG in iwl4965

[Gábor Stefanik]

On Thu, Dec 20, 2012 at 11:25 AM, Danilo <dantard@unizar.es> wrote:
> Danilo <dantard@...> writes:
>
>>
>> Hello,
>> I figured out that the command:
>>
>> iw dev wlan0 set bitrates legacy-5 24
>>
>> has different behaviors in different devices.
>>
>> With iwl3945 wireless cards, it fixes the rate at 24Mbps ALSO for multicast
>> frames while in iwl4965 cards, it doesn't.
>>
>> In both cases I tried with ubuntu linux 12.04 and kernel-3.2.0-32-generic
> using
>> iwl4965/iwl_legacy driver for 4965 and iwl3945/iwl_legacy driver for 3945.
>>
>> I've also tried with compat-wireless-3.6, same result.
>>
>> What's the expected behavior?
>>
>> Thanks in advance,
>>  D. Tardioli
>>
>> --
>> To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
>> the body of a message to majordomo@...
>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>>
>
> Hello,
> I answer myself:
> I've tried with ath5k-compatible card and it behaves like iwl3945.
> It means that when fixed the bitrates with a single value, the card always use
> that bitrate ALSO for broadcast frames.
>
> The iwl4965 doesn't behave this way.
> Any suggestion on how to solve the problem?

IIRC iwl4965 uses its own rate control algorithm (a while ago, it was
called "iwl-agn-rs", before the iwlegacy split). I think you should
look for the problem there.

-- 
Vista: [V]iruses, [I]ntruders, [S]pyware, [T]rojans and [A]dware. :-)

Re: Incoherency in iw (or mac80211 or drivers) behavior -- possible BUG in iwl4965

[Danilo]

Gábor Stefanik <netrolller.3d@...> writes:


> 
> IIRC iwl4965 uses its own rate control algorithm (a while ago, it was
> called "iwl-agn-rs", before the iwlegacy split). I think you should
> look for the problem there.
> 

Thanks for the answer.
In fact I looked at it as well and I tried to force iwl4965 to use 'minstrel' or 
'pid' algorithm hacking the code of the mac80211 with scarce success.
Do you know what is the correct way of selecting the desire rate control 
algorithm?

Thanks again.