[PATCH rtw-next 04/10] wifi: rtw89: drop packet offload entry on H2C addition failure to avoid scan issue

[Ping-Ke Shih <pkshih@realtek.com>]

From: Dian-Syuan Yang <dian_syuan0116@realtek.com>

A special case is when C2H done ack has been completed, but the
corresponding packet offload response has not actually been received,
which causes the add packet offload to fail. In this state, firmware
treats the entry as added, so subsequent add requests for the same id
are rejected as duplicates. To recover from this, send a delete packet
offload H2C command to roll back the normal state. It has been tested and
verified to have no functional side effect.

Signed-off-by: Dian-Syuan Yang <dian_syuan0116@realtek.com>
Signed-off-by: Ping-Ke Shih <pkshih@realtek.com>
---
 drivers/net/wireless/realtek/rtw89/fw.c | 26 ++++++++++++++++++++++---
 1 file changed, 23 insertions(+), 3 deletions(-)

diff --git a/drivers/net/wireless/realtek/rtw89/fw.c b/drivers/net/wireless/realtek/rtw89/fw.c
index d6a594b75ab2..342f95d41c02 100644
--- a/drivers/net/wireless/realtek/rtw89/fw.c
+++ b/drivers/net/wireless/realtek/rtw89/fw.c
@@ -6443,8 +6443,8 @@ int rtw89_fw_h2c_del_pkt_offload(struct rtw89_dev *rtwdev, u8 id)
 	return 0;
 }
 
-int rtw89_fw_h2c_add_pkt_offload(struct rtw89_dev *rtwdev, u8 *id,
-				 struct sk_buff *skb_ofld)
+static int __rtw89_fw_h2c_add_pkt_offload(struct rtw89_dev *rtwdev, u8 *id,
+					  struct sk_buff *skb_ofld)
 {
 	struct rtw89_wait_info *wait = &rtwdev->mac.fw_ofld_wait;
 	struct sk_buff *skb;
@@ -6486,13 +6486,33 @@ int rtw89_fw_h2c_add_pkt_offload(struct rtw89_dev *rtwdev, u8 *id,
 		rtw89_debug(rtwdev, RTW89_DBG_FW,
 			    "failed to add pkt ofld: id %d, ret %d\n",
 			    alloc_id, ret);
+		/*
+		 * Firmware may consider that it has added this entry
+		 * successfully even though the H2C return timeout.
+		 * Send a delete H2C command to drop it, and thus the
+		 * next add on the same id won't be rejected as duplicate.
+		 */
+		rtw89_fw_h2c_del_pkt_offload(rtwdev, alloc_id);
 		rtw89_core_release_bit_map(rtwdev->pkt_offload, alloc_id);
-		return ret;
+
+		return -EAGAIN;
 	}
 
 	return 0;
 }
 
+int rtw89_fw_h2c_add_pkt_offload(struct rtw89_dev *rtwdev, u8 *id,
+				 struct sk_buff *skb_ofld)
+{
+	int ret;
+
+	ret = __rtw89_fw_h2c_add_pkt_offload(rtwdev, id, skb_ofld);
+	if (ret == -EAGAIN)
+		ret = __rtw89_fw_h2c_add_pkt_offload(rtwdev, id, skb_ofld);
+
+	return ret;
+}
+
 static
 int rtw89_fw_h2c_scan_list_offload_ax(struct rtw89_dev *rtwdev, int ch_num,
 				      struct list_head *chan_list)
-- 
2.25.1