net: hns3: optimize the CSQ cmd error handling

If CMDQ ring is full, hclge_cmd_send may return directly, but IMP still
working and HW pointer changed, SW ring pointer do not match the HW
pointer. This patch update the SW pointer every time when the space is
full, so it can work normally next time if IMP and HW still working.
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_cmd.c

@@ -232,6 +232,7 @@ static int hclge_cmd_check_retval(struct hclge_hw *hw, struct hclge_desc *desc,
 int hclge_cmd_send(struct hclge_hw *hw, struct hclge_desc *desc, int num)
 {
 	struct hclge_dev *hdev = container_of(hw, struct hclge_dev, hw);
+	struct hclge_cmq_ring *csq = &hw->cmq.csq;
 	struct hclge_desc *desc_to_use;
 	bool complete = false;
 	u32 timeout = 0;
@@ -241,8 +242,16 @@ int hclge_cmd_send(struct hclge_hw *hw, struct hclge_desc *desc, int num)
 
 	spin_lock_bh(&hw->cmq.csq.lock);
 
-	if (num > hclge_ring_space(&hw->cmq.csq) ||
-	    test_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state)) {
+	if (test_bit(HCLGE_STATE_CMD_DISABLE, &hdev->state)) {
+		spin_unlock_bh(&hw->cmq.csq.lock);
+		return -EBUSY;
+	}
+
+	if (num > hclge_ring_space(&hw->cmq.csq)) {
+		/* If CMDQ ring is full, SW HEAD and HW HEAD may be different,
+		 * need update the SW HEAD pointer csq->next_to_clean
+		 */
+		csq->next_to_clean = hclge_read_dev(hw, HCLGE_NIC_CSQ_HEAD_REG);
 		spin_unlock_bh(&hw->cmq.csq.lock);
 		return -EBUSY;
 	}
@@ -280,7 +289,7 @@ int hclge_cmd_send(struct hclge_hw *hw, struct hclge_desc *desc, int num)
 	}
 
 	if (!complete) {
-		retval = -EAGAIN;
+		retval = -EBADE;
 	} else {
 		retval = hclge_cmd_check_retval(hw, desc, num, ntc);
 	}

drivers/net/ethernet/hisilicon/hns3/hns3vf/hclgevf_cmd.c

@@ -188,6 +188,7 @@ void hclgevf_cmd_setup_basic_desc(struct hclgevf_desc *desc,
 int hclgevf_cmd_send(struct hclgevf_hw *hw, struct hclgevf_desc *desc, int num)
 {
 	struct hclgevf_dev *hdev = (struct hclgevf_dev *)hw->hdev;
+	struct hclgevf_cmq_ring *csq = &hw->cmq.csq;
 	struct hclgevf_desc *desc_to_use;
 	bool complete = false;
 	u32 timeout = 0;
@@ -199,8 +200,17 @@ int hclgevf_cmd_send(struct hclgevf_hw *hw, struct hclgevf_desc *desc, int num)
 
 	spin_lock_bh(&hw->cmq.csq.lock);
 
-	if (num > hclgevf_ring_space(&hw->cmq.csq) ||
-	    test_bit(HCLGEVF_STATE_CMD_DISABLE, &hdev->state)) {
+	if (test_bit(HCLGEVF_STATE_CMD_DISABLE, &hdev->state)) {
+		spin_unlock_bh(&hw->cmq.csq.lock);
+		return -EBUSY;
+	}
+
+	if (num > hclgevf_ring_space(&hw->cmq.csq)) {
+		/* If CMDQ ring is full, SW HEAD and HW HEAD may be different,
+		 * need update the SW HEAD pointer csq->next_to_clean
+		 */
+		csq->next_to_clean = hclgevf_read_dev(hw,
+						      HCLGEVF_NIC_CSQ_HEAD_REG);
 		spin_unlock_bh(&hw->cmq.csq.lock);
 		return -EBUSY;
 	}
@@ -263,14 +273,13 @@ int hclgevf_cmd_send(struct hclgevf_hw *hw, struct hclgevf_desc *desc, int num)
 	}
 
 	if (!complete)
-		status = -EAGAIN;
+		status = -EBADE;
 
 	/* Clean the command send queue */
 	handle = hclgevf_cmd_csq_clean(hw);
-	if (handle != num) {
+	if (handle != num)
 		dev_warn(&hdev->pdev->dev,
 			 "cleaned %d, need to clean %d\n", handle, num);
-	}
 
 	spin_unlock_bh(&hw->cmq.csq.lock);