Re: [RFC/RFT 3/4] mt76x02: do not set protection on set_rts_threshold callback

[Stanislaw Gruszka <sgruszka@redhat.com>]

On Tue, Dec 04, 2018 at 11:45:09AM +0100, Stanislaw Gruszka wrote:

> Only OFDM_PROT_CFG is configured there based on legacy proto
> value. I'm not sure how handle CCK_PROT_CFG.
> 
> > > -	mt76_rmw(dev, MT_MM20_PROT_CFG,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_MM40_PROT_CFG,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_GF20_PROT_CFG,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_GF40_PROT_CFG,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_TX_PROT_CFG6,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_TX_PROT_CFG7,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > > -	mt76_rmw(dev, MT_TX_PROT_CFG8,
> > > -		 MT_PROT_CFG_CTRL | MT_PROT_CFG_RTS_THRESH, data);
> > 
> > Removing these lines we are no longer able to configure protection for VHT
> > rates. Do we have an equivalent for them in vht_capab?
> 
> Actually it's not based on HT capabilities but by on ht operation and
> it's modified dynamically by hostapd based on what stations are
> associated. For STA mode it's provided by remote AP via HT operation IE.
> 
> VHT Operation IE do not define protection. Seems interoperability with
> legacy STA's is not allowed for VHT, so leaving default values from
> initvals where PROT bits are 0 (none protection) is right thing to do.

But vendor driver change the VHT protection bits based on HT
operation element, with the comment:

"TODO: shiang-6590, fix me for this protection mechanism"

So I'm not sure any longer what correct behaviour should be for 
TX_PROT_CFG{6,7,8}.

Regards
Stanislaw