net: mhi: Get rid of local rx queue count

Use the new mhi_get_free_desc_count helper to track queue usage
instead of relying on the locally maintained rx_queued count.
Signed-off-by: Loic Poulain <loic.poulain@linaro.org>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/mhi_net.c

@@ -25,7 +25,6 @@ struct mhi_net_stats {
 	u64_stats_t tx_bytes;
 	u64_stats_t tx_errors;
 	u64_stats_t tx_dropped;
-	atomic_t rx_queued;
 	struct u64_stats_sync tx_syncp;
 	struct u64_stats_sync rx_syncp;
 };
@@ -138,9 +137,9 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
 {
 	struct mhi_net_dev *mhi_netdev = dev_get_drvdata(&mhi_dev->dev);
 	struct sk_buff *skb = mhi_res->buf_addr;
-	int remaining;
+	int free_desc_count;
 
-	remaining = atomic_dec_return(&mhi_netdev->stats.rx_queued);
+	free_desc_count = mhi_get_free_desc_count(mhi_dev, DMA_FROM_DEVICE);
 
 	if (unlikely(mhi_res->transaction_status)) {
 		dev_kfree_skb_any(skb);
@@ -175,7 +174,7 @@ static void mhi_net_dl_callback(struct mhi_device *mhi_dev,
 	}
 
 	/* Refill if RX buffers queue becomes low */
-	if (remaining <= mhi_netdev->rx_queue_sz / 2)
+	if (free_desc_count >= mhi_netdev->rx_queue_sz / 2)
 		schedule_delayed_work(&mhi_netdev->rx_refill, 0);
 }
 
@@ -222,7 +221,7 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
 	struct sk_buff *skb;
 	int err;
 
-	while (atomic_read(&mhi_netdev->stats.rx_queued) < mhi_netdev->rx_queue_sz) {
+	while (!mhi_queue_is_full(mdev, DMA_FROM_DEVICE)) {
 		skb = netdev_alloc_skb(ndev, size);
 		if (unlikely(!skb))
 			break;
@@ -235,8 +234,6 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
 			break;
 		}
 
-		atomic_inc(&mhi_netdev->stats.rx_queued);
-
 		/* Do not hog the CPU if rx buffers are consumed faster than
 		 * queued (unlikely).
 		 */
@@ -244,7 +241,7 @@ static void mhi_net_rx_refill_work(struct work_struct *work)
 	}
 
 	/* If we're still starved of rx buffers, reschedule later */
-	if (unlikely(!atomic_read(&mhi_netdev->stats.rx_queued)))
+	if (mhi_get_free_desc_count(mdev, DMA_FROM_DEVICE) == mhi_netdev->rx_queue_sz)
 		schedule_delayed_work(&mhi_netdev->rx_refill, HZ / 2);
 }