[PATCH 2/2] r8152: Add macpassthru support for ThinkPad Thunderbolt 3 Dock Gen 2

[Kai-Heng Feng <kai.heng.feng@canonical.com>]

ThinkPad Thunderbolt 3 Dock Gen 2 is another docking station that uses
RTL8153 based USB ethernet.

The device supports macpassthru, but it failed to pass the test of -AD,
-BND and -BD. Simply bypass these tests since the device supports this
feature just fine.

Also the ACPI objects have some differences between Dell's and Lenovo's,
so make those ACPI infos no longer hardcoded.

BugLink: https://bugs.launchpad.net/bugs/1827961

Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
---
 drivers/net/usb/cdc_ether.c |  7 ++++
 drivers/net/usb/r8152.c     | 65 ++++++++++++++++++++++++++-----------
 2 files changed, 53 insertions(+), 19 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 32f53de5b1fe..92751f6e792d 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -766,6 +766,13 @@ static const struct usb_device_id	products[] = {
 	.driver_info = 0,
 },
 
+/* ThinkPad Thunderbolt 3 Dock Gen 2 (based on Realtek RTL8153) */
+{
+	USB_DEVICE_AND_INTERFACE_INFO(LENOVO_VENDOR_ID, 0x3082, USB_CLASS_COMM,
+			USB_CDC_SUBCLASS_ETHERNET, USB_CDC_PROTO_NONE),
+	.driver_info = 0,
+},
+
 /* Lenovo Thinkpad USB 3.0 Ethernet Adapters (based on Realtek RTL8153) */
 {
 	USB_DEVICE_AND_INTERFACE_INFO(LENOVO_VENDOR_ID, 0x7205, USB_CLASS_COMM,
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index 1a987d4e45ab..65bdb745860c 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -658,6 +658,8 @@ enum rtl_register_content {
 #define RTL8152_NAPI_WEIGHT	64
 #define rx_reserved_size(x)	((x) + VLAN_ETH_HLEN + ETH_FCS_LEN + \
 				 sizeof(struct rx_desc) + RX_ALIGN)
+/* Device quirks */
+#define R8152_QUIRK_LENOVO_MACPASSTHRU		BIT(1)
 
 /* rtl8152 flags */
 enum rtl8152_flags {
@@ -670,6 +672,7 @@ enum rtl8152_flags {
 	SCHEDULE_TASKLET,
 	GREEN_ETHERNET,
 	DELL_TB_RX_AGG_BUG,
+	LENOVO_MACPASSTHRU,
 };
 
 /* Define these values to match your device */
@@ -1408,38 +1411,57 @@ static int vendor_mac_passthru_addr_read(struct r8152 *tp, struct sockaddr *sa)
 	int ret = -EINVAL;
 	u32 ocp_data;
 	unsigned char buf[6];
-
-	/* test for -AD variant of RTL8153 */
-	ocp_data = ocp_read_word(tp, MCU_TYPE_USB, USB_MISC_0);
-	if ((ocp_data & AD_MASK) == 0x1000) {
-		/* test for MAC address pass-through bit */
-		ocp_data = ocp_read_byte(tp, MCU_TYPE_USB, EFUSE);
-		if ((ocp_data & PASS_THRU_MASK) != 1) {
-			netif_dbg(tp, probe, tp->netdev,
-				  "No efuse for RTL8153-AD MAC pass through\n");
-			return -ENODEV;
-		}
+	bool bypass_test;
+	char *mac_obj_name;
+	acpi_object_type mac_obj_type;
+	int mac_strlen;
+
+	if (test_bit(LENOVO_MACPASSTHRU, &tp->flags)) {
+		bypass_test = true;
+		mac_obj_name = "\\MACA";
+		mac_obj_type = ACPI_TYPE_STRING;
+		mac_strlen = 0x16;
 	} else {
-		/* test for RTL8153-BND and RTL8153-BD */
-		ocp_data = ocp_read_byte(tp, MCU_TYPE_USB, USB_MISC_1);
-		if ((ocp_data & BND_MASK) == 0 && (ocp_data & BD_MASK) == 0) {
-			netif_dbg(tp, probe, tp->netdev,
-				  "Invalid variant for MAC pass through\n");
-			return -ENODEV;
+		bypass_test = false;
+		mac_obj_name = "\\_SB.AMAC";
+		mac_obj_type = ACPI_TYPE_BUFFER;
+		mac_strlen = 0x17;
+	}
+
+	if (!bypass_test) {
+		/* test for -AD variant of RTL8153 */
+		ocp_data = ocp_read_word(tp, MCU_TYPE_USB, USB_MISC_0);
+		if ((ocp_data & AD_MASK) == 0x1000) {
+			/* test for MAC address pass-through bit */
+			ocp_data = ocp_read_byte(tp, MCU_TYPE_USB, EFUSE);
+			if ((ocp_data & PASS_THRU_MASK) != 1) {
+				netif_dbg(tp, probe, tp->netdev,
+						"No efuse for RTL8153-AD MAC pass through\n");
+				return -ENODEV;
+			}
+		} else {
+			/* test for RTL8153-BND and RTL8153-BD */
+			ocp_data = ocp_read_byte(tp, MCU_TYPE_USB, USB_MISC_1);
+			if ((ocp_data & BND_MASK) == 0 && (ocp_data & BD_MASK) == 0) {
+				netif_dbg(tp, probe, tp->netdev,
+						"Invalid variant for MAC pass through\n");
+				return -ENODEV;
+			}
 		}
 	}
 
 	/* returns _AUXMAC_#AABBCCDDEEFF# */
-	status = acpi_evaluate_object(NULL, "\\_SB.AMAC", NULL, &buffer);
+	status = acpi_evaluate_object(NULL, mac_obj_name, NULL, &buffer);
 	obj = (union acpi_object *)buffer.pointer;
 	if (!ACPI_SUCCESS(status))
 		return -ENODEV;
-	if (obj->type != ACPI_TYPE_BUFFER || obj->string.length != 0x17) {
+	if (obj->type != mac_obj_type || obj->string.length != mac_strlen) {
 		netif_warn(tp, probe, tp->netdev,
 			   "Invalid buffer for pass-thru MAC addr: (%d, %d)\n",
 			   obj->type, obj->string.length);
 		goto amacout;
 	}
+
 	if (strncmp(obj->string.pointer, "_AUXMAC_#", 9) != 0 ||
 	    strncmp(obj->string.pointer + 0x15, "#", 1) != 0) {
 		netif_warn(tp, probe, tp->netdev,
@@ -6626,6 +6648,9 @@ static int rtl8152_probe(struct usb_interface *intf,
 		netdev->hw_features &= ~NETIF_F_RXCSUM;
 	}
 
+	if (id->driver_info & R8152_QUIRK_LENOVO_MACPASSTHRU)
+		set_bit(LENOVO_MACPASSTHRU, &tp->flags);
+
 	if (le16_to_cpu(udev->descriptor.bcdDevice) == 0x3011 && udev->serial &&
 	    (!strcmp(udev->serial, "000001000000") ||
 	     !strcmp(udev->serial, "000002000000"))) {
@@ -6754,6 +6779,8 @@ static const struct usb_device_id rtl8152_table[] = {
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x304f, 0)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x3062, 0)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x3069, 0)},
+	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x3082,
+			R8152_QUIRK_LENOVO_MACPASSTHRU)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x7205, 0)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x720c, 0)},
 	{REALTEK_USB_DEVICE(VENDOR_ID_LENOVO,  0x7214, 0)},
-- 
2.17.1