net: ll_temac: Avoid ndo_start_xmit returning NETDEV_TX_BUSY

[ Upstream commit f6396341194234e9b01cd7538bc2c6ac4501ab14 ] As documented in Documentation/networking/driver.rst, the ndo_start_xmit method must not return NETDEV_TX_BUSY under any normal circumstances, and as recommended, we simply stop the tx queue in advance, when there is a risk that the next xmit would cause a NETDEV_TX_BUSY return. Signed-off-by: Esben Haabendal <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Sasha Levin <[email protected]>
akeromi · Jun 30, 2021 · a5ccdf7 · a5ccdf7
1 parent 987c6da
commit a5ccdf7
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -736,6 +736,11 @@ temac_start_xmit(struct sk_buff *skb, struct net_device *ndev)
 	/* Kick off the transfer */
 	lp->dma_out(lp, TX_TAILDESC_PTR, tail_p); /* DMA start */
 
+	if (temac_check_tx_bd_space(lp, MAX_SKB_FRAGS + 1)) {
+		netdev_info(ndev, "%s -> netif_stop_queue\n", __func__);
+		netif_stop_queue(ndev);
+	}
+
 	return NETDEV_TX_OK;
 }