From: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
Date: Tue, 3 Feb 2026 15:55:31 +0000 (+0800)
Subject: wifi: mt76: avoid to set ACK for MCU command if wait_resp is not set
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=169c83d3df95b57e787174454332e01eb1b823ed;p=thirdparty%2Flinux.git

wifi: mt76: avoid to set ACK for MCU command if wait_resp is not set

When wait_resp is not set but the ACK option is enabled in the MCU TXD,
the ACK event is enqueued to the MCU event queue without being dequeued
by the original MCU command request.

Any orphaned ACK events will only be removed from the queue when another
MCU command requests a response. Due to sequence index mismatches, these
events are discarded one by one until a matching sequence index is found.

However, if several MCU commands that do not require a response continue
to fill up the event queue, there is a risk that when an MCU command with
wait_resp enabled is issued, it may dequeue the wrong event skb,
especially if the queue contains events with all possible sequence
indices.

Signed-off-by: StanleyYP Wang <StanleyYP.Wang@mediatek.com>
Signed-off-by: Shayne Chen <shayne.chen@mediatek.com>
Link: https://patch.msgid.link/20260203155532.1098290-3-shayne.chen@mediatek.com
Signed-off-by: Felix Fietkau <nbd@nbd.name>
---

diff --git a/drivers/net/wireless/mediatek/mt76/mcu.c b/drivers/net/wireless/mediatek/mt76/mcu.c
index 535c3d8a9cc0d..cbfb3bbec5031 100644
--- a/drivers/net/wireless/mediatek/mt76/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mcu.c
@@ -98,7 +98,7 @@ retry:
 	/* orig skb might be needed for retry, mcu_skb_send_msg consumes it */
 	if (orig_skb)
 		skb_get(orig_skb);
-	ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, &seq);
+	ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, wait_resp ? &seq : NULL);
 	if (ret < 0)
 		goto out;
 
diff --git a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
index 13182a69eec91..ee0fb3c45ca24 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7996/mcu.c
@@ -325,13 +325,12 @@ mt7996_mcu_send_message(struct mt76_dev *mdev, struct sk_buff *skb,
 		uni_txd->pkt_type = MCU_PKT_ID;
 		uni_txd->seq = seq;
 
-		if (cmd & __MCU_CMD_FIELD_QUERY)
-			uni_txd->option = MCU_CMD_UNI_QUERY_ACK;
-		else
-			uni_txd->option = MCU_CMD_UNI_EXT_ACK;
+		uni_txd->option = MCU_CMD_UNI;
+		if (!(cmd & __MCU_CMD_FIELD_QUERY))
+			uni_txd->option |= MCU_CMD_SET;
 
-		if (mcu_cmd == MCU_UNI_CMD_SDO)
-			uni_txd->option &= ~MCU_CMD_ACK;
+		if (wait_seq)
+			uni_txd->option |= MCU_CMD_ACK;
 
 		if ((cmd & __MCU_CMD_FIELD_WA) && (cmd & __MCU_CMD_FIELD_WM))
 			uni_txd->s2d_index = MCU_S2D_H2CN;