[ath9k-devel] Why not running at n speed?

[Luis R. Rodriguez <lrodriguez@atheros.com>]

On Tue, Feb 03, 2009 at 01:40:50AM -0800, Tamas Selmeci wrote:
> Hi all!
> 
> I'm using AR5416-based (TP-Link TL-WN861N) n-card with ath9k
> (compat-wireless-2009-01-25) with 2.6.27-rc6 kernel on ARM (Intel XScal
> IXP425). We have two Netgear n-routers, but the connection speed
> (measured by simple FTP transfer) doesn't seem to be 'n'. ~2 weeks ago
> there was a thread on this list about n speed, I made a quick compare
> between my logs and the logs found on the list, 

> and noticed that my card
> never operates on 5Ghz frequencies.
> 
> (The card is switched to DE regulatory)

Your logs showed:

> phy0: Atheros AR5416 MAC/BB Rev:2 AR2122 RF Rev:81: mem=0xc4900000, irq=27

AR2122 is a single band 2.4 GHz 2x2 MIMO radio -- it has
two integrated 2.4 GHz radios, supports both 20 MHz and 40 MHz
bandwidths.

> Do you have any idea? What is wrong?

You reported two things:

1. Not getting good throughput
2. No 5 GHz.

As for your first issue can you confirm you have set up your access points
in 802.11n mode, and see if you can enable HT40. If you have no legacy products
(802.11bg) I would recommend to go 'Pure N' or aka 'Greenfield'.

As for your second issue, your concern about not getting 5 GHz channels,
your card seems to be single band so it does not have any 5 GHz radios.
You can always install iw and run 'iw list' to confirm. Not all cards are
dual band. Dual band card are quite rare, specially AR5416 cards from what
I have seen.

http://wireless.kernel.org/en/users/Documentation/iw

> Here are the logs:
> 
> With router Netgear WNR854T:

<-- snip -->

> With router Netgear WNR2000:

Instead of logs please show iperf tests for now, from the station using
the ath9k driver to a box connected directly to an APs through ethernet.

  Luis