r8152: fix the force speed doesn't work for RTL8156

[ Upstream commit 45bf944e6703d43fe5e285808312acd8a34c1a24 ]

It needs to set mdio force mode. Otherwise, link off always occurs when
setting force speed.

Fixes: 195aae321c82 ("r8152: support new chips")
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index d3da350..3364e54 100644 (file)
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -6584,6 +6584,21 @@ static bool rtl8153_in_nway(struct r8152 *tp)
                return true;
 }
 
+static void r8156_mdio_force_mode(struct r8152 *tp)
+{
+       u16 data;
+
+       /* Select force mode through 0xa5b4 bit 15
+        * 0: MDIO force mode
+        * 1: MMD force mode
+        */
+       data = ocp_reg_read(tp, 0xa5b4);
+       if (data & BIT(15)) {
+               data &= ~BIT(15);
+               ocp_reg_write(tp, 0xa5b4, data);
+       }
+}
+
 static void set_carrier(struct r8152 *tp)
 {
        struct net_device *netdev = tp->netdev;
@@ -8016,6 +8031,7 @@ static void r8156_init(struct r8152 *tp)
        ocp_data |= ACT_ODMA;
        ocp_write_byte(tp, MCU_TYPE_USB, USB_BMU_CONFIG, ocp_data);
 
+       r8156_mdio_force_mode(tp);
        rtl_tally_reset(tp);
 
        tp->coalesce = 15000;   /* 15 us */
@@ -8145,6 +8161,7 @@ static void r8156b_init(struct r8152 *tp)
        ocp_data &= ~(RX_AGG_DISABLE | RX_ZERO_EN);
        ocp_write_word(tp, MCU_TYPE_USB, USB_USB_CTRL, ocp_data);
 
+       r8156_mdio_force_mode(tp);
        rtl_tally_reset(tp);
 
        tp->coalesce = 15000;   /* 15 us */