[PATCH 5.4 140/222] net: hns3: pad the short frame before sending to the hardware

Greg Kroah-Hartman
2020-01-22T13:23:55Z

From: Yunsheng Lin <linyunsheng@huawei.com>

[ Upstream commit 36c67349a1a1c88b9cf11d7ca7762ababdb38867 ]

The hardware can not handle short frames below or equal to 32
bytes according to the hardware user manual, and it will trigger
a RAS error when the frame's length is below 33 bytes.

This patch pads the SKB when skb->len is below 33 bytes before
sending it to hardware.

Fixes: 76ad4f0ee747 ("net: hns3: Add support of HNS3 Ethernet Driver for hip08 SoC")
Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/net/ethernet/hisilicon/hns3/hns3_enet.c | 6 ++++++
1 file changed, 6 insertions(+)

--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -54,6 +54,8 @@ MODULE_PARM_DESC(debug, " Network interf
#define HNS3_INNER_VLAN_TAG 1
#define HNS3_OUTER_VLAN_TAG 2

+#define HNS3_MIN_TX_LEN 33U
+
/* hns3_pci_tbl - PCI Device ID Table
*
* Last entry must be all 0s
@@ -1329,6 +1331,10 @@ netdev_tx_t hns3_nic_net_xmit(struct sk_
int ret;
int i;

+ /* Hardware can only handle short frames above 32 bytes */
+ if (skb_put_padto(skb, HNS3_MIN_TX_LEN))
+ return NETDEV_TX_OK;
+
/* Prefetch the data used later */
prefetch(skb->data);