Lorenzo Bianconi [off-list ref] writes:

[...]

quoted

-	buf->xdpf = xdpf;
-	tx_desc->command = MVNETA_TXD_FLZ_DESC;
-	tx_desc->buf_phys_addr = dma_addr;
-	tx_desc->data_size = xdpf->len;
+	/*last descriptor */
+	if (tx_desc)
+		tx_desc->command |= MVNETA_TXD_L_DESC | MVNETA_TXD_Z_PAD;

       When is this condition not taken ? You initialize tx_desc        to
NULL, but it seems to me like you always set it inside        the for loop
to the output of mvneta_txq_next_desc_get()        which doesn't look like
it returns NULL. The for loop runs 1 iteration or `sinfo->nr_frage + 1`
iterations (which also equals or larger than 1).

ack, right. I will fix it in v3.

Regards,
Lorenzo

quoted

-	mvneta_txq_inc_put(txq);
-	txq->pending++;
-	txq->count++;
+	txq->pending += num_frames;
+	txq->count += num_frames;
 	return MVNETA_XDP_TX;
 }