From af15946aa081dbcd0bec7d507a2b2db4e6b6cda5 Mon Sep 17 00:00:00 2001
From: Andrew Thomas <andrew.thomas@oracle.com>
Date: Mon, 18 Jun 2018 11:56:06 -0700
Subject: [PATCH] dwc2 USB controller hangs with lan78xx

This bug is the combination of dwc2 USB controller and lan78xx
USB ethernet controller, which is the combination in use on
the Raspberry Pi Model 3 B+.

When the host attempts to receive a packet, but a packet has not
arrived, the lan78xx controller responds by setting BIR
(Bulk-In Empty Response) to NAK. Unfortunately, this hangs
the USB controller and requires the USB controller to
be reset.

The fix proposed is to have the lan78xx controller respond
by setting BIR to ZLP.

Signed-off-by: Andrew Thomas <andrew.thomas@oracle.com>
Tested-by: Peter Robinson <pbrobinson@gmail.com>
Reviewed-by: Alexander Graf <agraf@suse.de>
---
 drivers/usb/eth/lan78xx.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/usb/eth/lan78xx.c b/drivers/usb/eth/lan78xx.c
index c5ff3797cf..e8ee6650bc 100644
--- a/drivers/usb/eth/lan78xx.c
+++ b/drivers/usb/eth/lan78xx.c
@@ -296,7 +296,7 @@ static int lan78xx_basic_reset(struct usb_device *udev,
 	ret = lan7x_read_reg(udev, LAN78XX_USB_CFG0, &val);
 	if (ret)
 		return ret;
-	val |= LAN78XX_USB_CFG0_BIR;
+	val &= ~LAN78XX_USB_CFG0_BIR;
 	return lan7x_write_reg(udev, LAN78XX_USB_CFG0, val);
 }
 
-- 
2.39.5