net: hns3: add Asym Pause support to fix autoneg problem

Local device and link partner config auto-negotiation on both,
local device config pause frame use as: rx on/tx off,
link partner config pause frame use as: rx off/tx on.

We except the result is:
Local device:
Autonegotiate:  on
RX:             on
TX:             off
RX negotiated:  on
TX negotiated:  off

Link partner:
Autonegotiate:  on
RX:             off
TX:             on
RX negotiated:  off
TX negotiated:  on

But actually, the result of Local device and link partner is both:
Autonegotiate:  on
RX:             off
TX:             off
RX negotiated:  off
TX negotiated:  off

The root cause is that the supported flag is has only Pause,
reference to the function genphy_config_advert():
static int genphy_config_advert(struct phy_device *phydev)
{
	...
	linkmode_and(phydev->advertising, phydev->advertising,
		     phydev->supported);
	...
}
The pause frame use of link partner is rx off/tx on, so its
advertising only set the bit Asym_Pause, and the supported is
only set the bit Pause, so the result of linkmode_and(), is
rx off/tx off.

This patch adds Asym_Pause to the supported flag to fix it.
Signed-off-by: Yonglong Liu <liuyonglong@huawei.com>
Signed-off-by: Peng Li <lipeng321@huawei.com>
Signed-off-by: Huazhong Tan <tanhuazhong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_main.c

@@ -1061,6 +1061,7 @@ static void hclge_parse_copper_link_mode(struct hclge_dev *hdev,
 	linkmode_set_bit(ETHTOOL_LINK_MODE_Autoneg_BIT, supported);
 	linkmode_set_bit(ETHTOOL_LINK_MODE_TP_BIT, supported);
 	linkmode_set_bit(ETHTOOL_LINK_MODE_Pause_BIT, supported);
+	linkmode_set_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT, supported);
 }
 
 static void hclge_parse_link_mode(struct hclge_dev *hdev, u8 speed_ability)

drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_mdio.c

@@ -224,6 +224,13 @@ int hclge_mac_connect_phy(struct hnae3_handle *handle)
 	linkmode_and(phydev->supported, phydev->supported, mask);
 	linkmode_copy(phydev->advertising, phydev->supported);
 
+	/* supported flag is Pause and Asym Pause, but default advertising
+	 * should be rx on, tx on, so need clear Asym Pause in advertising
+	 * flag
+	 */
+	linkmode_clear_bit(ETHTOOL_LINK_MODE_Asym_Pause_BIT,
+			   phydev->advertising);
+
 	return 0;
 }