2023-05-17 09:29:07

by Deren Wu

Subject: [PATCH v2] wifi: mt76: mt7921: fix skb leak by txs missing in AMSDU

txs may be dropped if the frame is aggregated in AMSDU. When the problem
shows up, some SKBs would be hold in driver to cause network stopped
temporarily. Even if the problem can be recovered by txs timeout handling,
mt7921 still need to disable txs in AMSDU to avoid this issue.

Cc: [email protected]
Fixes: 163f4d22c118 ("mt76: mt7921: add MAC support")
Reviewed-by: Shayne Chen <[email protected]>
Signed-off-by: Deren Wu <[email protected]>
---
v2: * update operation for booleans, not bitfields (suggested by Simon Horman)
* rectify fixes tag for downstream backport
---
drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c | 7 +++++--
1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
index ee0fbfcd07d6..a548b8debf5f 100644
--- a/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
+++ b/drivers/net/wireless/mediatek/mt76/mt76_connac_mac.c
@@ -495,6 +495,7 @@ void mt76_connac2_mac_write_txwi(struct mt76_dev *dev, __le32 *txwi,
BSS_CHANGED_BEACON_ENABLED));
bool inband_disc = !!(changed & (BSS_CHANGED_UNSOL_BCAST_PROBE_RESP |
BSS_CHANGED_FILS_DISCOVERY));
+ bool amsdu_en = wcid->amsdu;

if (vif) {
struct mt76_vif *mvif = (struct mt76_vif *)vif->drv_priv;
@@ -554,12 +555,14 @@ void mt76_connac2_mac_write_txwi(struct mt76_dev *dev, __le32 *txwi,
txwi[4] = 0;

val = FIELD_PREP(MT_TXD5_PID, pid);
- if (pid >= MT_PACKET_ID_FIRST)
+ if (pid >= MT_PACKET_ID_FIRST) {
val |= MT_TXD5_TX_STATUS_HOST;
+ amsdu_en = amsdu_en && !is_mt7921(dev);
+ }

txwi[5] = cpu_to_le32(val);
txwi[6] = 0;
- txwi[7] = wcid->amsdu ? cpu_to_le32(MT_TXD7_HW_AMSDU) : 0;
+ txwi[7] = amsdu_en ? cpu_to_le32(MT_TXD7_HW_AMSDU) : 0;

if (is_8023)
mt76_connac2_mac_write_txwi_8023(txwi, skb, wcid);
--
2.18.0

2023-05-17 15:30:00

by Simon Horman

Subject: Re: [PATCH v2] wifi: mt76: mt7921: fix skb leak by txs missing in AMSDU

On Wed, May 17, 2023 at 05:18:24PM +0800, Deren Wu wrote:
> txs may be dropped if the frame is aggregated in AMSDU. When the problem
> shows up, some SKBs would be hold in driver to cause network stopped
> temporarily. Even if the problem can be recovered by txs timeout handling,
> mt7921 still need to disable txs in AMSDU to avoid this issue.
>
> Cc: [email protected]
> Fixes: 163f4d22c118 ("mt76: mt7921: add MAC support")
> Reviewed-by: Shayne Chen <[email protected]>
> Signed-off-by: Deren Wu <[email protected]>
> ---
> v2: * update operation for booleans, not bitfields (suggested by Simon Horman)
> * rectify fixes tag for downstream backport

Thanks, LGTM.

Reviewed-by: Simon Horman <[email protected]>