From 8b0178d1d736ed3759e122549ab6b3dcb98a68fe Mon Sep 17 00:00:00 2001
From: Felix Fietkau <nbd@nbd.name>
Date: Tue, 13 Aug 2024 20:19:32 +0200
Subject: [PATCH] wifi: mt76: mt7915: retry mcu messages

In some cases MCU messages can get lost. Instead of failing completely,
attempt to recover by re-sending them.

Signed-off-by: Felix Fietkau <nbd@nbd.name>
---
 mcu.c        | 20 ++++++++++++++++++++
 mt76.h       |  3 +++
 mt7915/mcu.c |  7 ++-----
 3 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/mcu.c b/mcu.c
index a8cafa39..98da82b7 100644
--- a/mcu.c
+++ b/mcu.c
@@ -73,6 +73,8 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
 				  int cmd, bool wait_resp,
 				  struct sk_buff **ret_skb)
 {
+	unsigned int retry = 0;
+	struct sk_buff *orig_skb = NULL;
 	unsigned long expires;
 	int ret, seq;
 
@@ -81,6 +83,14 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
 
 	mutex_lock(&dev->mcu.mutex);
 
+	if (dev->mcu_ops->mcu_skb_prepare_msg) {
+		ret = dev->mcu_ops->mcu_skb_prepare_msg(dev, skb, cmd, &seq);
+		if (ret < 0)
+			goto out;
+	}
+
+retry:
+	orig_skb = skb_get(skb);
 	ret = dev->mcu_ops->mcu_skb_send_msg(dev, skb, cmd, &seq);
 	if (ret < 0)
 		goto out;
@@ -94,6 +104,14 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
 
 	do {
 		skb = mt76_mcu_get_response(dev, expires);
+		if (!skb && !test_bit(MT76_MCU_RESET, &dev->phy.state) &&
+		    retry++ < dev->mcu_ops->max_retry) {
+			dev_err(dev->dev, "Retry message %08x (seq %d)\n",
+				cmd, seq);
+			skb = orig_skb;
+			goto retry;
+		}
+
 		ret = dev->mcu_ops->mcu_parse_response(dev, cmd, skb, seq);
 		if (!ret && ret_skb)
 			*ret_skb = skb;
@@ -101,7 +119,9 @@ int mt76_mcu_skb_send_and_get_msg(struct mt76_dev *dev, struct sk_buff *skb,
 			dev_kfree_skb(skb);
 	} while (ret == -EAGAIN);
 
+
 out:
+	dev_kfree_skb(orig_skb);
 	mutex_unlock(&dev->mcu.mutex);
 
 	return ret;
diff --git a/mt76.h b/mt76.h
index a538307b..4b78cd1b 100644
--- a/mt76.h
+++ b/mt76.h
@@ -234,11 +234,14 @@ struct mt76_queue {
 };
 
 struct mt76_mcu_ops {
+	unsigned int max_retry;
 	u32 headroom;
 	u32 tailroom;
 
 	int (*mcu_send_msg)(struct mt76_dev *dev, int cmd, const void *data,
 			    int len, bool wait_resp);
+	int (*mcu_skb_prepare_msg)(struct mt76_dev *dev, struct sk_buff *skb,
+				   int cmd, int *seq);
 	int (*mcu_skb_send_msg)(struct mt76_dev *dev, struct sk_buff *skb,
 				int cmd, int *seq);
 	int (*mcu_parse_response)(struct mt76_dev *dev, int cmd,
diff --git a/mt7915/mcu.c b/mt7915/mcu.c
index 86b1266a..59ebaee5 100644
--- a/mt7915/mcu.c
+++ b/mt7915/mcu.c
@@ -191,11 +191,6 @@ mt7915_mcu_send_message(struct mt76_dev *mdev, struct sk_buff *skb,
 {
 	struct mt7915_dev *dev = container_of(mdev, struct mt7915_dev, mt76);
 	enum mt76_mcuq_id qid;
-	int ret;
-
-	ret = mt76_connac2_mcu_fill_message(mdev, skb, cmd, wait_seq);
-	if (ret)
-		return ret;
 
 	if (cmd == MCU_CMD(FW_SCATTER))
 		qid = MT_MCUQ_FWDL;
@@ -2381,7 +2376,9 @@ int mt7915_mcu_init_firmware(struct mt7915_dev *dev)
 int mt7915_mcu_init(struct mt7915_dev *dev)
 {
 	static const struct mt76_mcu_ops mt7915_mcu_ops = {
+		.max_retry = 3,
 		.headroom = sizeof(struct mt76_connac2_mcu_txd),
+		.mcu_skb_prepare_msg = mt76_connac2_mcu_fill_message,
 		.mcu_skb_send_msg = mt7915_mcu_send_message,
 		.mcu_parse_response = mt7915_mcu_parse_response,
 	};