[ath9k-devel] AR9380 - Transmit power control per packet

[Aleksey Shevkov <a.shevkov@infinet.ru>]

On Sat, Jul 09, 2011 at 08:21:20AM +0800, Adrian Chadd wrote:
> On 8 July 2011 22:19, Alex Hacker <hacker@epn.ru> wrote:
> > Oh sorry, let me take last words back. Robert is right it does not work with AR9380.
> > Power control mechanism does not depend on AR_PHY_POWER_TX_RATE_MAX_TPC_ENABLE bit.
> > The AR_PHY_POWER_TX_RATE_MAX register contains a different value 0x00367044 on AR9380 and
> > 0x0000007f on older chips.
> 
> Except that the AR9300 TPC enable code does exactly the same as the
> TPC enable code for the AR5416 series chips.
> 
Shure exactly same code. I havn't any other source of information about AR9380
PHY except the ar9003_phy.h file.

> By the way, the 11n rate scenario code doesn't have any per-rate TPC
> code in it. Only the TX power for rate series 0 is set. Is this
> potentially causing you problems?
> 
I test it with single series NoAck packets (XmitDataTries0 = 1, XmitPower != 0).
The AR9380 transmit at the power configured for self generated packets
AR_PHY_POWER_TX_RATEn registers not at the power set in AR_XmitPower field of
ctl11 word of TX descriptor.

> From a cursory examination of the AR9300 code (and I should say, I've
> not even used an AR9300 yet, let alone tinkered with the TPC stuff) it
> looks all very straightforward. Unless some other chip functionality
> is required that hasn't been ported to ath9k, it "should just work".
> 
My primary distrust falls on the AR_PHY_POWER_TX_RATE_MAX register. Although
the AR9380 chip has very different PHY, this register is defined at the same
adress as in the older chips (I'm afraid the definition is copy-pasted from
ar9002_phy.h file). This register holds the value prior to the last write, i.e.
REG_WRITE(AR_PHY_POWER_TX_RATE_MAX,x)
REG_WRITE(AR_PHY_POWER_TX_RATE_MAX,y)
REG_READ(AR_PHY_POWER_TX_RATE_MAX) == x
This is not look like ordinary PHY register.

> Sorry, I can't be more helpful than that.
> 
Thank you Adrian for you attention to this problem! I am ensured that all
together we found the solution.

> (Also, it'd be nice if someone contributed per-packet TPC support -
> proper support at that! - to ath9k. :)
> 
I think about it just some time later. Currently really very busy on my primary
job. I found some other HW problems on AR9380 which does not allow me to
finish MIMO 3x3 support for our equipment.

> 
> adrian