quoted

quoted

+static netdev_tx_t nct6694_canfd_start_xmit(struct sk_buff *skb,
+                                       struct net_device *ndev)
+{
+   struct nct6694_canfd_priv *priv = netdev_priv(ndev);
+   struct nct6694 *nct6694 = priv->nct6694;
+   struct canfd_frame *cf = (struct canfd_frame *)skb->data;
+   struct net_device_stats *stats = &ndev->stats;
+   int can_idx = priv->can_idx;
+   u32 txid = 0;
+   int i;
+   unsigned int echo_byte;
+   u8 data_buf[REQUEST_CAN_CMD10_LEN] = {0};
+
+   if (can_dropped_invalid_skb(ndev, skb))
+           return NETDEV_TX_OK;
+
+   /*
+    * No check for NCT66794 because the TX bit is read-clear
+    * and may be read-cleared by other function
+    * Just check the result of tx command.
+    */

Where do you check the result of the TX command?

quoted

+   /* Check if the TX buffer is full */

Where's the check if the TX buffer is full?

Sorry for the missing code. It will be checked in tx_work().
If nct6694_write_msg() for CMD10 returns an error related to CAN_Deliver,
I will add error handling in the next patch.

quoted

quoted

+   netif_stop_queue(ndev);
+
+   if (can_idx == 0)
+           data_buf[CAN_TAG_IDX] = CAN_TAG_CAN0;
+   else
+           data_buf[CAN_TAG_IDX] = CAN_TAG_CAN1;
+
+   if (cf->can_id & CAN_EFF_FLAG) {
+           txid = cf->can_id & CAN_EFF_MASK;
+           /*
+            * In case the Extended ID frame is transmitted, the
+            * standard and extended part of the ID are swapped
+            * in the register, so swap them back to send the
+            * correct ID.
+            */
+           data_buf[CAN_FLAG_IDX] |= CAN_FLAG_EFF;
+   } else {
+           txid = cf->can_id & CAN_SFF_MASK;
+   }
+
+   set_buf32(&data_buf[CAN_ID_IDX], txid);
+
+   data_buf[CAN_DLC_IDX] = cf->len;
+
+   if ((priv->can.ctrlmode & CAN_CTRLMODE_FD) && can_is_canfd_skb(skb)) {
+           data_buf[CAN_FLAG_IDX] |= CAN_FLAG_FD;
+           if (cf->flags & CANFD_BRS)
+                   data_buf[CAN_FLAG_IDX] |= CAN_FLAG_BRS;
+   }
+
+   if (cf->can_id & CAN_RTR_FLAG)
+           data_buf[CAN_FLAG_IDX] |= CAN_FLAG_RTR;
+
+   /* set data to buf */
+   for (i = 0; i < cf->len; i++)
+           data_buf[CAN_DATA_IDX + i] = *(u8 *)(cf->data + i);
+
+   can_put_echo_skb(skb, ndev, 0, 0);
+
+   memcpy(priv->data_buf, data_buf, REQUEST_CAN_CMD10_LEN);
+   queue_work(nct6694->async_workqueue, &priv->tx_work);
+
+   stats->tx_bytes += cf->len;
+   stats->tx_packets++;
+   echo_byte = can_get_echo_skb(ndev, 0, NULL);
+
+   netif_wake_queue(ndev);

How do you make sure that the tx_work has finished?
Once you wake the queue, the xmit function can be called again. If your
tx_work has not finished, you'll overwrite the priv->data_buf.

Do you get a CAN TX complete message/IRQ from your device?

I will move the code that needs to confirm the completion of TX transmission
to tx_work().

In tx_work(), CMD2 CAN_Event's TX_EVT will first confirm TX_FIFO_EMPTY,
ensuring transmission is complete.


Best regards,
Ming