[ath9k-devel] Antenna Configuration

[ath9k-devel] Antenna Configuration

[Robert Meschke]

  Hi Mike,

I had the same problem and wrote a workaround for it. The possible 
Chainmask-Configuration is retrieved from the EEPROM of your card by the 
driver. Normally all Antennas are activated. There is no API for 
Antenna-Configuration in Ath9k/Cfg80211... and therefore no API in 
Userspace, too. Try to apply the attached patch. It should give you the 
possibility to set up your antenna-config by using special module 
params. I'm using an embedded system with up to four mini-pci-slots. So 
I added the params chainconf0 - chainconf3. Usage:

 > insmod/modprobe ath9k chainconf0=11:22:33:44:55:66#2x2 (3x3, 2x3, 1x1 
...)

(macadress of the interface + MIMO-representation)

I tested the patch with a spectrum analyser attached to the 
antenna-connectors and by transmitting data. The patch works well for me 
with AR9160.

good luck :-)

Robert
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[ath9k-devel] Antenna Configuration

[Adrian Chadd]

Hi!

Did you test this in 11abg mode? Or just 11n?

I've got a 3x3 AR9160 card which I'm considering disabling radio
chains on to compare performance. This seems like it's a useful thing.

Whilst talking about antennas, do you/anyone know how TX/RX antenna
setting/diversity works on the AR9160/AR9106 in 11abg mode(s) ? I've
been investigating it with a spectrum analyser for the TX path but I'm
curious about the specifics on how both TX/RX radios and antennas
works in the non-n modes.

Thanks,


Adrian

On 13 September 2010 23:56, Robert Meschke <r_meschke@yahoo.de> wrote:
> ?Hi Mike,
>
> I had the same problem and wrote a workaround for it. The possible
> Chainmask-Configuration is retrieved from the EEPROM of your card by the
> driver. Normally all Antennas are activated. There is no API for
> Antenna-Configuration in Ath9k/Cfg80211... and therefore no API in
> Userspace, too. Try to apply the attached patch. It should give you the
> possibility to set up your antenna-config by using special module params.
> I'm using an embedded system with up to four mini-pci-slots. So I added the
> params chainconf0 - chainconf3. Usage:
>
>> insmod/modprobe ath9k chainconf0=11:22:33:44:55:66#2x2 (3x3, 2x3, 1x1 ...)
>
> (macadress of the interface + MIMO-representation)
>
> I tested the patch with a spectrum analyser attached to the
> antenna-connectors and by transmitting data. The patch works well for me
> with AR9160.
>
> good luck :-)
>
> Robert
>
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel at lists.ath9k.org
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
>

[ath9k-devel] Antenna Configuration

[Mike Pithouse]

Hi Robert,

That looks excellent - thank you.

I'll give this a try.

Cheers, Mike.


-----Original Message-----
From: Robert Meschke [mailto:r_meschke at yahoo.de] 
Sent: 13 September 2010 16:57
To: ath9k-devel at venema.h4ckr.net
Cc: Mike Pithouse
Subject: [ath9k-devel] Antenna Configuration

  Hi Mike,

I had the same problem and wrote a workaround for it. The possible
Chainmask-Configuration is retrieved from the EEPROM of your card by the
driver. Normally all Antennas are activated. There is no API for
Antenna-Configuration in Ath9k/Cfg80211... and therefore no API in
Userspace, too. Try to apply the attached patch. It should give you the
possibility to set up your antenna-config by using special module
params. I'm using an embedded system with up to four mini-pci-slots. So
I added the params chainconf0 - chainconf3. Usage:

 > insmod/modprobe ath9k chainconf0=11:22:33:44:55:66#2x2 (3x3, 2x3, 1x1
...)

(macadress of the interface + MIMO-representation)

I tested the patch with a spectrum analyser attached to the
antenna-connectors and by transmitting data. The patch works well for me
with AR9160.

good luck :-)

Robert

[ath9k-devel] Antenna Configuration

[Robert Meschke]

  Hi Adrian,

look at the main.c of ath9k.

/*
  * Update tx/rx chainmask. For legacy association,
  * hard code chainmask to 1x1, for 11n association, use
  * the chainmask configuration, for bt coexistence, use
  * the chainmask configuration even in legacy mode.
  */
void ath_update_chainmask(struct ath_softc *sc, int is_ht)
{
     struct ath_hw *ah = sc->sc_ah;
     struct ath_common *common = ath9k_hw_common(ah);

     if ((sc->sc_flags & SC_OP_SCANNING) || is_ht ||
         (ah->btcoex_hw.scheme != ATH_BTCOEX_CFG_NONE)) {
         common->tx_chainmask = ah->caps.tx_chainmask;
         common->rx_chainmask = ah->caps.rx_chainmask;
     } else {
         common->tx_chainmask = 1;
         common->rx_chainmask = 1;
     }

     ath_print(common, ATH_DBG_CONFIG,
           "tx chmask: %d, rx chmask: %d\n",
           common->tx_chainmask,
           common->rx_chainmask);
}

This function is called on every channel change. If there is no 11n mode 
1x1 is used (when no bt coexistence is used)   -> always chain0 is used. 
So i think that antenna diversity is impossible in legacy mode!? with no 
bt coexictence.  I don't know the term bt coexistence (Bluetooth - 
coexictence!?)
My patch only overides the capability field. I don't touch this 
function. So I think my patch can only work well in 11n mode.

Btw. If you setup 2x2 on AR9160 you will use chain0 an chain1. I got 
strange behaviour, when I tried to use for example chain 0 and chain2

Robert

[ath9k-devel] Antenna Configuration

[Mike Pithouse]

Hi,

 

Is there any way to set antenna config using the ath9k driver?  eg
disable certain antenna(e), switch to 3t3r, 2t2r etc.

 

I'd guessed it would be possible with the 'iw' command but can't find
anything by experimentation or Googling (except some stuff for ath5k
which doesn't work for me).

 

Cheers, Mike.

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