mt76: add support for reporting tx status with skb

MT76x2/MT76x0 has somewhat unreliable tx status reporting, and for that
reason the driver currently does not report per-skb tx ack status at all.
This breaks things like client idle polling, which relies on the tx ack
status of a transmitted nullfunc frame.

This patch adds code to report skb-attached tx status if requested by
mac80211 or the rate control module. Since tx status is polled from a
simple FIFO register, the code needs to account for the possibility of
tx status events getting lost.

The code keeps a list of skbs for which tx status is required and passes
them to mac80211 once tx status has been filled in and the DMA queue is
done with it.
If a tx status event is not received after one second, the status rates
are cleared, and a succesful ACK is indicated to avoid spurious disassoc
during assoc or client polling.

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 1 insertions, 0 deletions

diff --git a/drivers/net/wireless/mediatek/mt76/usb.c b/drivers/net/wireless/mediatek/mt76/usb.c
index 24d41288ea59..b061263453d4 100644
--- a/drivers/net/wireless/mediatek/mt76/usb.c
+++ b/drivers/net/wireless/mediatek/mt76/usb.c
@@ -700,6 +700,7 @@ mt76u_tx_queue_skb(struct mt76_dev *dev, struct mt76_queue *q,
 	if (q->queued == q->ndesc)
 		return -ENOSPC;
 
+	skb->prev = skb->next = NULL;
 	err = dev->drv->tx_prepare_skb(dev, NULL, skb, q, wcid, sta, NULL);
 	if (err < 0)
 		return err;