From f727ed8a112355c964b25a472e6da361864ee574 Mon Sep 17 00:00:00 2001
From: Michael Brown <mcb30@ipxe.org>
Date: Fri, 3 Jul 2020 20:17:25 +0100
Subject: [PATCH] [axge] Reapply USB device configuration when opening network
 device

When connected to a USB3 port, the AX88179 seems to have an
approximately 50% chance of producing a USB transaction error on each
of its three endpoints after being closed and reopened.  The root
cause is unclear, but rewriting the USB device configuration value
seems to clear whatever internal error state has accumulated.

Signed-off-by: Michael Brown <mcb30@ipxe.org>
---
 src/drivers/net/axge.c | 9 +++++++++
 src/drivers/net/axge.h | 2 ++
 2 files changed, 11 insertions(+)

diff --git a/src/drivers/net/axge.c b/src/drivers/net/axge.c
index 1106c1e6f..fb274d24f 100644
--- a/src/drivers/net/axge.c
+++ b/src/drivers/net/axge.c
@@ -531,6 +531,13 @@ static int axge_open ( struct net_device *netdev ) {
 	uint16_t rcr;
 	int rc;
 
+	/* Reapply device configuration to avoid transaction errors */
+	if ( ( rc = usb_set_configuration ( axge->usb, axge->config ) ) != 0 ) {
+		DBGC ( axge, "AXGE %p could not set configuration: %s\n",
+		       axge, strerror ( rc ) );
+		goto err_set_configuration;
+	}
+
 	/* Open USB network device */
 	if ( ( rc = usbnet_open ( &axge->usbnet ) ) != 0 ) {
 		DBGC ( axge, "AXGE %p could not open: %s\n",
@@ -567,6 +574,7 @@ static int axge_open ( struct net_device *netdev ) {
  err_write_mac:
 	usbnet_close ( &axge->usbnet );
  err_open:
+ err_set_configuration:
 	return rc;
 }
 
@@ -674,6 +682,7 @@ static int axge_probe ( struct usb_function *func,
 	axge->usb = usb;
 	axge->bus = usb->port->hub->bus;
 	axge->netdev = netdev;
+	axge->config = config->config;
 	usbnet_init ( &axge->usbnet, func, &axge_intr_operations,
 		      &axge_in_operations, &axge_out_operations );
 	usb_refill_init ( &axge->usbnet.intr, 0, 0, AXGE_INTR_MAX_FILL );
diff --git a/src/drivers/net/axge.h b/src/drivers/net/axge.h
index 6183b4e70..e22e0ec47 100644
--- a/src/drivers/net/axge.h
+++ b/src/drivers/net/axge.h
@@ -145,6 +145,8 @@ struct axge_device {
 	struct net_device *netdev;
 	/** USB network device */
 	struct usbnet_device usbnet;
+	/** Device configuration */
+	unsigned int config;
 	/** Link state has changed */
 	int check_link;
 };