Hi Vadim,

On Wed, 24 Jan 2024 10:03:45 +0000
Vadim Fedorenko [off-list ref] wrote:

[...]

quoted

+static void qmc_hcld_recv_complete(void *context, size_t length, unsigned int flags)
+{
+	struct qmc_hdlc_desc *desc = context;
+	struct net_device *netdev = desc->netdev;
+	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(desc->netdev);  

a line above desc->netdev was stored in netdev. better to reuse it and 
make declaration part consistent with qmc_hcld_xmit_complete

Yes.
Will updated in the next iteration.

[...]

quoted

+static netdev_tx_t qmc_hdlc_xmit(struct sk_buff *skb, struct net_device *netdev)
+{
+	struct qmc_hdlc *qmc_hdlc = netdev_to_qmc_hdlc(netdev);
+	struct qmc_hdlc_desc *desc;
+	unsigned long flags;
+	int ret;
+
+	spin_lock_irqsave(&qmc_hdlc->tx_lock, flags);
+	desc = &qmc_hdlc->tx_descs[qmc_hdlc->tx_out];
+	if (desc->skb) {
+		/* Should never happen.
+		 * Previous xmit should have already stopped the queue.
+		 */  

according to the comment it's better to make if(unlikely(desc->skb)) or
even WARN_ONCE()

Indeed. I will use WARN_ONCE() in the next iteration.

Thanks for your review,
Hervé