[PATCH] mt76: fix monitor rx FCS error in DFS channel

[Deren Wu]

Hi Lore,

On Wed, 2022-03-16 at 16:15 +0100, Lorenzo Bianconi wrote:
> > From: Deren Wu <deren.wu at mediatek.com>
> > 
> > When setup monitor mode in DFS channel, mt76 send CH_SWITCH_DFS to
> > fw for channel config. This would cause rx performance bad while
> > monitoring frames. Settings CH_SWITCH_NORMAL in monitor mode would
> > get the same performance as normal channels.
> 
> Hi Deren,
> 
> > 
> > Reviewed-by: Shayne Chen <shayne.chen at mediatek.com>
> > Signed-off-by: Deren Wu <deren.wu at mediatek.com>
> > ---
> >  drivers/net/wireless/mediatek/mt76/mt7615/mcu.c | 3 ++-
> >  drivers/net/wireless/mediatek/mt76/mt7915/mcu.c | 3 ++-
> >  drivers/net/wireless/mediatek/mt76/mt7921/mcu.c | 3 ++-
> >  3 files changed, 6 insertions(+), 3 deletions(-)
> > 
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> > b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> > index 390add3144c2..97e2a85cb728 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7615/mcu.c
> > @@ -2151,7 +2151,8 @@ int mt7615_mcu_set_chan_info(struct
> > mt7615_phy *phy, int cmd)
> >  		.center_chan2 = ieee80211_frequency_to_channel(freq2),
> >  	};
> >  
> > -	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
> > +	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
> > +	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
> 
> is this patch compliant with 802.11h DFS standard?

Monitor mode would not tx packets and still follow standard. We will
keep tracking this point to avoid violations.


Regards,
Deren


> 
> Regards,
> Lorenzo
> 
> >  		req.switch_reason = CH_SWITCH_NORMAL;
> >  	else if (phy->mt76->hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
> >  		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> > b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> > index 10dc4bf5adec..c56d48342aaf 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7915/mcu.c
> > @@ -2833,7 +2833,8 @@ int mt7915_mcu_set_chan_info(struct
> > mt7915_phy *phy, int cmd)
> >  	}
> >  #endif
> >  
> > -	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
> > +	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
> > +	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
> >  		req.switch_reason = CH_SWITCH_NORMAL;
> >  	else if (phy->mt76->hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
> >  		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;
> > diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
> > b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
> > index 5ef8b24f0ab3..da2be050ed7c 100644
> > --- a/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
> > +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mcu.c
> > @@ -863,7 +863,8 @@ int mt7921_mcu_set_chan_info(struct mt7921_phy
> > *phy, int cmd)
> >  	else
> >  		req.channel_band = chandef->chan->band;
> >  
> > -	if (cmd == MCU_EXT_CMD(SET_RX_PATH))
> > +	if (cmd == MCU_EXT_CMD(SET_RX_PATH) ||
> > +	    dev->mt76.hw->conf.flags & IEEE80211_CONF_MONITOR)
> >  		req.switch_reason = CH_SWITCH_NORMAL;
> >  	else if (dev->mt76.hw->conf.flags & IEEE80211_CONF_OFFCHANNEL)
> >  		req.switch_reason = CH_SWITCH_SCAN_BYPASS_DPD;
> > -- 
> > 2.18.0
> >