r8152: disable RX aggregation on Dell TB16 dock

r8153 on Dell TB15/16 dock corrupts rx packets.

This change is suggested by Realtek. They guess that the XHCI controller
doesn't have enough buffer, and their guesswork is correct, once the RX
aggregation gets disabled, the issue is gone.

ASMedia is currently working on a real sulotion for this issue.

Dell and ODM confirm the bcdDevice and iSerialNumber is unique for TB16.

Note that TB15 has different bcdDevice and iSerialNumber, which are not
unique values. If you still have TB15, please contact Dell to replace it
with TB16.

BugLink: https://bugs.launchpad.net/bugs/1729674
Cc: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/usb/r8152.c b/drivers/net/usb/r8152.c
index d51d9ab..0657203 100644
--- a/drivers/net/usb/r8152.c
+++ b/drivers/net/usb/r8152.c
@@ -606,6 +606,7 @@
 	PHY_RESET,
 	SCHEDULE_NAPI,
 	GREEN_ETHERNET,
+	DELL_TB_RX_AGG_BUG,
 };
 
 /* Define these values to match your device */
@@ -1798,6 +1799,9 @@
 		dev_kfree_skb_any(skb);
 
 		remain = agg_buf_sz - (int)(tx_agg_align(tx_data) - agg->head);
+
+		if (test_bit(DELL_TB_RX_AGG_BUG, &tp->flags))
+			break;
 	}
 
 	if (!skb_queue_empty(&skb_head)) {
@@ -4133,6 +4137,9 @@
 	/* rx aggregation */
 	ocp_data = ocp_read_word(tp, MCU_TYPE_USB, USB_USB_CTRL);
 	ocp_data &= ~(RX_AGG_DISABLE | RX_ZERO_EN);
+	if (test_bit(DELL_TB_RX_AGG_BUG, &tp->flags))
+		ocp_data |= RX_AGG_DISABLE;
+
 	ocp_write_word(tp, MCU_TYPE_USB, USB_USB_CTRL, ocp_data);
 
 	rtl_tally_reset(tp);
@@ -5207,6 +5214,12 @@
 		netdev->hw_features &= ~NETIF_F_RXCSUM;
 	}
 
+	if (le16_to_cpu(udev->descriptor.bcdDevice) == 0x3011 &&
+	    udev->serial && !strcmp(udev->serial, "000001000000")) {
+		dev_info(&udev->dev, "Dell TB16 Dock, disable RX aggregation");
+		set_bit(DELL_TB_RX_AGG_BUG, &tp->flags);
+	}
+
 	netdev->ethtool_ops = &ops;
 	netif_set_gso_max_size(netdev, RTL_LIMITED_TSO_SIZE);