[PATCH wireless] wifi: mt76: mt76x02: restart mac_work after a channel change

[Rosen Penev <rosenp@gmail.com>]

Since the channel change code moved to the core, mt76_set_channel()
cancels phy->mac_work before calling the driver's set_channel op. The
mt7603, mt7615 and mt7915 set_channel ops queue mac_work again, but the
mt76x0 and mt76x2 ones do not, and they only queue it in their start
op. After the first channel change, which happens on every interface
up, association and scan, mt76x02_mac_work never runs again.

mt76x02_mac_work calls mt76_tx_status_check() to time out frames that
wait for a TX status report. Without it, frames whose report is lost
stay in the wcid pktid idr until another report happens to sweep them.
On an MT7612U station sending 25 Mbit/s of UDP, 48 such frames piled
up within seconds. They kept their AQL airtime and their socket memory,
and the sender blocked on a full socket send buffer for up to 30 s
until a connection monitor probe swept them. The work also collects the
survey, A-MPDU and EDCCA statistics and checks for MAC errors.

Queue mac_work again at the end of the set_channel ops.

Fixes: f4fdd7716290 ("wifi: mt76: partially move channel change code to core")
Assisted-by: LLM
Signed-off-by: Rosen Penev <rosenp@gmail.com>
---
 drivers/net/wireless/mediatek/mt76/mt76x0/main.c     | 2 ++
 drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c | 2 ++
 drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c | 2 ++
 3 files changed, 6 insertions(+)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76x0/main.c b/drivers/net/wireless/mediatek/mt76/mt76x0/main.c
index a5c40d350612..a2763cf648b5 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x0/main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x0/main.c
@@ -26,6 +26,8 @@ int mt76x0_set_channel(struct mt76_phy *mphy)
 		tasklet_enable(&dev->dfs_pd.dfs_tasklet);
 	}
 	mt76x02_pre_tbtt_enable(dev, true);
+	ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mphy.mac_work,
+				     MT_MAC_WORK_INTERVAL);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
index 550644676201..ab4d0e3f79bc 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/pci_main.c
@@ -49,6 +49,8 @@ int mt76x2e_set_channel(struct mt76_phy *phy)
 
 	tasklet_enable(&dev->dfs_pd.dfs_tasklet);
 	tasklet_enable(&dev->mt76.pre_tbtt_tasklet);
+	ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mphy.mac_work,
+				     MT_MAC_WORK_INTERVAL);
 
 	return 0;
 }
diff --git a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
index 66b06a493d95..57550ab3b7da 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76x2/usb_main.c
@@ -45,6 +45,8 @@ int mt76x2u_set_channel(struct mt76_phy *mphy)
 	mt76x2_mac_resume(dev);
 
 	mt76x02_pre_tbtt_enable(dev, true);
+	ieee80211_queue_delayed_work(mt76_hw(dev), &dev->mphy.mac_work,
+				     MT_MAC_WORK_INTERVAL);
 
 	return err;
 }
-- 
2.56.0