2012-12-20 10:25:18

by Danilo

[permalink] [raw]
Subject: Re: Incoherency in iw (or mac80211 or drivers) behavior -- possible BUG in iwl4965

Danilo <[email protected]> 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 [email protected]
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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.





2012-12-20 10:59:41

by Gábor Stefanik

[permalink] [raw]
Subject: Re: Incoherency in iw (or mac80211 or drivers) behavior -- possible BUG in iwl4965

On Thu, Dec 20, 2012 at 11:25 AM, Danilo <[email protected]> wrote:
> Danilo <[email protected]> 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 [email protected]
>> 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.

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