[PATCH mt76-next 03/27] wifi: mt76: mt7996: set sniffer mode on a radio that is already running

[Felix Fietkau <nbd@nbd.name>]

mt7996_add_interface() skips a radio that has MT76_STATE_RUNNING set,
and the skip covers both the start of the radio and the call to
mt7996_set_monitor(). mt7996_init_wiphy_band() sets
MT_WF_RFCR_DROP_OTHER_UC in phy->rxfilter on every band, and
mt7996_configure_filter() does not clear it, so only
mt7996_set_monitor() does. A monitor interface that is added while an
AP runs on the same radio thus receives no unicast frame addressed to
another device.

Start only an idle radio, but put every radio of a monitor interface
into sniffer mode. mt7996_remove_interface() already clears sniffer
mode whether the radio runs or not.

Fixes: 69d54ce7491d ("wifi: mt76: mt7996: switch to single multi-radio wiphy")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 drivers/net/wireless/mediatek/mt76/mt7996/main.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/main.c b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
index c04e980f6ee7..d013a472c28d 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/main.c
@@ -570,13 +570,14 @@ static int mt7996_add_interface(struct ieee80211_hw *hw,
 	for (i = 0; i < MT7996_MAX_RADIOS; i++) {
 		struct mt7996_phy *phy = dev->radio_phy[i];
 
-		if (!phy || !(wdev->radio_mask & BIT(i)) ||
-		    test_bit(MT76_STATE_RUNNING, &phy->mt76->state))
+		if (!phy || !(wdev->radio_mask & BIT(i)))
 			continue;
 
-		err = mt7996_run(phy);
-		if (err)
-			goto out;
+		if (!test_bit(MT76_STATE_RUNNING, &phy->mt76->state)) {
+			err = mt7996_run(phy);
+			if (err)
+				goto out;
+		}
 
 		if (vif->type == NL80211_IFTYPE_MONITOR)
 			mt7996_set_monitor(phy, true);
-- 
2.47.3