r8152: Disable PLA MCU clock speed down

PLA MCU clock speed down could only be enabled when tx/rx are disabled.
Otherwise, the packet loss may occur.
Signed-off-by: Hayes Wang <hayeswang@realtek.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/usb/r8152.c

@@ -324,6 +324,7 @@
 #define MAC_CLK_SPDWN_EN	BIT(15)
 
 /* PLA_MAC_PWR_CTRL3 */
+#define PLA_MCU_SPDWN_EN	BIT(14)
 #define PKT_AVAIL_SPDWN_EN	0x0100
 #define SUSPEND_SPDWN_EN	0x0004
 #define U1U2_SPDWN_EN		0x0002
@@ -5005,6 +5006,8 @@ static void rtl8153_down(struct r8152 *tp)
 
 static void rtl8153b_up(struct r8152 *tp)
 {
+	u32 ocp_data;
+
 	if (test_bit(RTL8152_UNPLUG, &tp->flags))
 		return;
 
@@ -5015,17 +5018,27 @@ static void rtl8153b_up(struct r8152 *tp)
 	r8153_first_init(tp);
 	ocp_write_dword(tp, MCU_TYPE_USB, USB_RX_BUF_TH, RX_THR_B);
 
+	ocp_data = ocp_read_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3);
+	ocp_data &= ~PLA_MCU_SPDWN_EN;
+	ocp_write_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3, ocp_data);
+
 	r8153_aldps_en(tp, true);
 	r8153b_u1u2en(tp, true);
 }
 
 static void rtl8153b_down(struct r8152 *tp)
 {
+	u32 ocp_data;
+
 	if (test_bit(RTL8152_UNPLUG, &tp->flags)) {
 		rtl_drop_queued_tx(tp);
 		return;
 	}
 
+	ocp_data = ocp_read_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3);
+	ocp_data |= PLA_MCU_SPDWN_EN;
+	ocp_write_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3, ocp_data);
+
 	r8153b_u1u2en(tp, false);
 	r8153_u2p3en(tp, false);
 	r8153b_power_cut_en(tp, false);
@@ -5521,6 +5534,10 @@ static void r8153b_init(struct r8152 *tp)
 	ocp_data |= MAC_CLK_SPDWN_EN;
 	ocp_write_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL2, ocp_data);
 
+	ocp_data = ocp_read_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3);
+	ocp_data &= ~PLA_MCU_SPDWN_EN;
+	ocp_write_word(tp, MCU_TYPE_PLA, PLA_MAC_PWR_CTRL3, ocp_data);
+
 	set_bit(GREEN_ETHERNET, &tp->flags);
 
 	/* rx aggregation */