Re: [PATCH 1/7] mt76x02: use mask for vifs

[Lorenzo Bianconi <lorenzo.bianconi@redhat.com>]

> On Fri, Jan 25, 2019 at 10:02:38AM +0100, Lorenzo Bianconi wrote:
> > > On Thu, Jan 24, 2019 at 11:20:42PM +0100, Lorenzo Bianconi wrote:
> > > > > > > 
> > > > > > > I guess this does not work if you add 2 vifs and then you remove the first one
> > > > > > > (you will end up with a wrong configuration in MT_MAC_ADDR_DW{0,1}). I guess
> > > > > > > the hw will not work well if MT_MAC_ADDR_DW{0,1} is not properly configured
> > > > > 
> > > > > Maybe I am missing something, but let's assume you add the interface vif0 with address
> > > > > 00:11:22:33:44:55 (MT_MAC_ADDR_DW{0,1} will be set to 00:11:22:33:44:55) and
> > > > > then you add vif1 with address 00:aa:bb:cc:dd:ee. If at some point you remove
> > > > > vif0 MT_MAC_ADDR_DW{0,1} will not be properly reconfigured. The problem will
> > > > > be more complex if you have more interfaces
> > > 
> > > Ok, so in remove_interface extra code can be added to implement that.
> 
> Something like this should address the issue you raised:
> 
> diff --git a/drivers/net/wireless/mediatek/mt76/mt76x02_util.c b/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
> index 3880caa0c64a..44b4af928a4e 100644
> --- a/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
> +++ b/drivers/net/wireless/mediatek/mt76/mt76x02_util.c
> @@ -320,6 +320,15 @@ void mt76x02_sta_remove(struct mt76_dev *mdev, struct ieee80211_vif *vif,
>  }
>  EXPORT_SYMBOL_GPL(mt76x02_add_interface);
>  
> +static void mt76x02_setaddr_iterator(void *data, u8 *mac,
> +                                     struct ieee80211_vif *vif)
> +{
> +	struct mt76x02_dev *dev = data;
> +
> +	if (!ether_addr_equal(dev->mt76.macaddr, vif->addr))
> +                mt76x02_mac_setaddr(dev, vif->addr);

This will end-up with multiple configurations if we have more than two
interfaces, right?

> +}
> +
>  void mt76x02_remove_interface(struct ieee80211_hw *hw,
>  			      struct ieee80211_vif *vif)
>  {
> @@ -328,6 +337,10 @@ void mt76x02_remove_interface(struct ieee80211_hw *hw,
>  
>  	mt76_txq_remove(&dev->mt76, vif->txq);
>  	dev->vif_mask &= ~BIT(mvif->idx);
> +
> +	if (hweight16(dev->vif_mask) == 1)
> +		ieee80211_iterate_interfaces(hw, 0, mt76x02_setaddr_iterator,
> +					     dev);

I guess we have the same issue if we have more than two interfaces and we
remove the first one that has been configured.
Moreover I am a little worried about tpt regressions with this patch.
Are you sure that if you use complete different mac addresses on a multivif scenario
you can get the same tpt on all the interfaces? Could you please provide some
tpt results?
Vendor driver relies on a strict scheme for mac addresses in multi-bss. If tpt is
nice I am ok with this patch

Regards,
Lorenzo

>  }
>  EXPORT_SYMBOL_GPL(mt76x02_remove_interface);