net: hns3: add dma_rmb() for rx description

[ Upstream commit d394d33bee22421b39a0bcdc51ca6d68ba308625 ]

HW can not guarantee complete write desc->rx.size, even though
HNS3_RXD_VLD_B has been set. Driver needs to add dma_rmb()
instruction to make sure desc->rx.size is always valid.

Fixes: e55970950556 ("net: hns3: Add handling of GRO Pkts not fully RX'ed in NAPI poll")
Signed-off-by: Jian Shen <shenjian15@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>

diff --git a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
index 1bf7a5f116a09a4cf211e25e3501ec9cd9d29774..882d2d2acdfa58ca106553560e2d2831a3929550 100644 (file)
--- a/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
+++ b/drivers/net/ethernet/hisilicon/hns3/hns3_enet.c
@@ -2476,6 +2476,8 @@ static int hns3_add_frag(struct hns3_enet_ring *ring, struct hns3_desc *desc,
                desc = &ring->desc[ring->next_to_clean];
                desc_cb = &ring->desc_cb[ring->next_to_clean];
                bd_base_info = le32_to_cpu(desc->rx.bd_base_info);
+               /* make sure HW write desc complete */
+               dma_rmb();
                if (!hnae3_get_bit(bd_base_info, HNS3_RXD_VLD_B))
                        return -ENXIO;