Re: [PATCH v3 2/4] rt2x00: remove confusing AGC register

[Daniel Golle <daniel@makrotopia.org>]

On Tue, Oct 09, 2018 at 02:47:48PM +0200, Stanislaw Gruszka wrote:
> Hi
> 
> On Tue, Oct 09, 2018 at 02:27:22PM +0200, Daniel Golle wrote:
> > On Tue, Oct 09, 2018 at 01:56:08PM +0200,  Gruszka wrote:
> > > Register 66 was causing issues on RT6352 if set to the same value as
> > > in MTK driver. With 1c reg value device was working fine in both HT20
> > > and HT40 modes.
> > 
> > My guess is that this may change once we add proper TSSI which involes
> > parts of AGC init as well. I suggest to add a comment in the code to
> > reflect that.
> 
> I don't understand what you suggest, could you be more specific ?

simply add these lines:
/*
 * Despite the vendor driver using different values here, use 0x1c
 * for now. This may have to be changed once TSSI got implemented
 */

> 
> > > diff --git a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> > > index 1a2bf6c49b82..3a04eaef8511 100644
> > > --- a/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> > > +++ b/drivers/net/wireless/ralink/rt2x00/rt2800lib.c
> > > @@ -3981,11 +3981,7 @@ static void rt2800_config_channel(struct rt2x00_dev *rt2x00dev,
> > >  		rt2800_bbp_write(rt2x00dev, 196, reg);
> > >  
> > >  		/* AGC init */
> > > -		if (rt2x00_rt(rt2x00dev, RT6352))
> > > -			reg = 0x04;
> > > -		else
> > > -			reg = rf->channel <= 14 ? 0x1c : 0x24;
> > > -
> > > +		reg = rf->channel <= 14 ? 0x1c : 0x24;
> > >  		reg += 2 * rt2x00dev->lna_gain;
> > 
> > We can summerize the two lines into
> > 		reg = 0x1c + (2 * rt2x00dev->lna_gain);
> > which is also what is was before introducing support for MT7620.
> 
> I think you mean
> 
> reg = (rf->channel <= 14 ? 0x1c : 0x24) + 2 * rt2x00dev->lna_gain; 
> 
> to do not break 5GHz support for RT5592.  I can change that in
> separate patch, since this one in not technically wrong.
> 
> Thanks
> Stanislaw
>