2019-03-21 21:52:08

by Lorenzo Bianconi

Subject: [PATCH] mt76: tx: check return value of tx_queue_skb in mt76_tx

Do not kick the queue if tx_queue_skb fails in mt76_tx

Signed-off-by: Lorenzo Bianconi <[email protected]>
---
drivers/net/wireless/mediatek/mt76/tx.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/tx.c b/drivers/net/wireless/mediatek/mt76/tx.c
index 60bbb6561d8f..833c414cea83 100644
--- a/drivers/net/wireless/mediatek/mt76/tx.c
+++ b/drivers/net/wireless/mediatek/mt76/tx.c
@@ -258,8 +258,8 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
{
struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb);
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *) skb->data;
+ int err, qid = skb_get_queue_mapping(skb);
struct mt76_queue *q;
- int qid = skb_get_queue_mapping(skb);

if (WARN_ON(qid >= MT_TXQ_PSD)) {
qid = MT_TXQ_BE;
@@ -286,7 +286,10 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
q = dev->q_tx[qid].q;

spin_lock_bh(&q->lock);
- dev->queue_ops->tx_queue_skb(dev, qid, skb, wcid, sta);
+ err = dev->queue_ops->tx_queue_skb(dev, qid, skb, wcid, sta);
+ if (err < 0)
+ goto out;
+
dev->queue_ops->kick(dev, q);

if (q->queued > q->ndesc - 8 && !q->stopped) {
@@ -294,6 +297,7 @@ mt76_tx(struct mt76_dev *dev, struct ieee80211_sta *sta,
q->stopped = true;
}

+out:
spin_unlock_bh(&q->lock);
}
EXPORT_SYMBOL_GPL(mt76_tx);
--
2.20.1

2019-03-23 11:36:41

by Felix Fietkau

Subject: Re: [PATCH] mt76: tx: check return value of tx_queue_skb in mt76_tx

On 2019-03-21 22:51, Lorenzo Bianconi wrote:
> Do not kick the queue if tx_queue_skb fails in mt76_tx
>
> Signed-off-by: Lorenzo Bianconi <[email protected]>
tx_queue_skb will fail only in rare corner cases, and kicking the queue
without adding extra packets is harmless.
Because of that, I think this patch is unnecessary.

- Felix