Atheros - txpower - Compex WLM54AG + WLM54AG-23

[Sam Leffler]

Johann Hugo wrote:
> I'm busy testing two wifi cards from Compex under FreeBSD 6.2-STABLE. The 
> WLM54AG card has a max txpower of 20dBm and the WLM54AG-23 has a max txpower 
> of 23dBm. 
> http://www.compex.com.sg/home/Datasheet/New_WLM_DSv1.9.pdf
> 
> The problem is that both cards produces the same RSSI value on my remote 
> station a couple of km's away from my test setup. If I do the same test with 
> the same cards under Ubuntu 6.06 then the  WLM54AG-23 produces a bigger RSSI 
> value on my remote station than the WLM54AG card.

Beware that rssi isn't necessarily indicative of tx power.  If you don't
put the cards on a spectrum analyzer or power meter you're just guessing.

> 
> Under FreeBSD, with a country code of 710 the max txpower can only go up-to 32 
> (16dbm) on both cards and vith a country code of 0 they can go upto 36 
> (18dbm). Under Ubunti I can set the max txpower of the WLM54AG card to 20dBm 
> and the WLM54AG-23 card to 23dBm.

Where do you get these numbers?  There was a hal bug I recently fixed
where the _reported_ max tx power obtained from the calibration data was
wrong.  Note that is REPORTED, the actual max tx power cap was correct
and you should see that measuring with a SA or power meter.

> 
> I'm not to sure if this is the right place to post my problem, or whether I 
> should rather try the MadWifi list or the manufacturer of the cards itself, 
> but it feels like it's related to FreeBSD.

It is unclear what is going on but there have been no hal changes that
would affect operation and/or cause operation to be different between
madwifi and freebsd.  I suggest you measure things properly and then
come back to me.

FWIW I've recently done extensive testing of tx power control for ath
devices with a variety of high power cards.  I am reasonably confident
the hal (and driver) are doing the right things.  There appear, however,
to be issues with at least one vendor's cards.  I've yet to reach
closure on the problem so cannot comment more--but in the end I was
forced to switch vendors because my project couldn't wait.

	Sam
> 
> Johann Hugo
> 
> Here is some more detail of my setup
> --------------------------------------------------------------------------------------------------------------
> 
> Local test side --- 2km wifi --- Remote side (RSSI)
> 
> Local station:
> wifi cards. Compex WLM54AG + WLM54AG-23
> Soekris net4526 running FreeBSD 6.2-STABLE #15: Mon Jan 29
> dmesg
> ath_hal: 0.9.20.3 (AR5210, AR5211, AR5212, RF5111, RF5112, RF2413, RF5413)
> ath0: <Atheros 5212> mem 0xa0000000-0xa000ffff irq 10 at device 17.0 on pci0
> ath0: [GIANT-LOCKED]
> ath0: Ethernet address: 00:80:48:41:49:3d
> ath0: mac 10.4 phy 6.1 radio 6.3
> 
> Remote station:
> wifi card = Aries5354
> Wrap 2C running 6.2-PRERELEASE #9: Tue Dec  5
> dmesg
> ath1: <Atheros 5212> mem 0x80080000-0x8008ffff irq 9 at device 17.0 on pci0
> ath1: [GIANT-LOCKED]
> ath1: Ethernet address: 00:02:6f:34:21:a0
> ath1: mac 5.6 phy 4.1 5ghz radio 1.7 2ghz radio 2.3
> 
> RSSI stats on remote side:
> -------------------------
> WLM54AG card
> 
> FeeBSD
> rodricks:~ > ifconfig ath1 list sta
> ADDR                   AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> 00:80:48:41:49:3d    0    5   2M   15    0     17  60368 IS   A
> 
> Ubuntu
> rodricks:~ > ifconfig ath1 list sta
> ADDR               AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> 00:80:48:41:49:3d    0    5   2M   13    0    108  61328 IS   A
> 
> 
> ----------------------
> WLM54AG-23 card
> 
> FreeBSD
> rodricks:~ > ifconfig ath1 list sta
> ADDR                   AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> 00:80:48:7e:60:17    0    5   1M   13    0  38066  47824 IS   A
> 
> countrycode = 0
> rodricks:~ > ifconfig ath1 list sta
> ADDR               AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> 00:80:48:7e:60:17    0    5   5M   15    0     43  51008 IS   A
> 
> Ubuntu
> rodricks:~ > ifconfig ath1 list sta
> ADDR               AID CHAN RATE RSSI IDLE  TXSEQ  RXSEQ CAPS FLAG
> 00:80:48:7e:60:17    0    5   5M   20    0     62   4672 IS   A    WME
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