[PATCH] usb: gadget: ether: Handle gadget driver registration in start and stop

[Zixun LI]

Revert part of 718f1d41 to move
 usb_gadget_register_driver()/usb_gadget_unregister_driver()
back to usb_eth_start()/usb_eth_stop().

usb_gadget_register_driver() will initialize the USB controller which
enters ready to connect state with pull-up resistor enabled.

>From the host's point of view, a device is ready to be enumerated.
However, since dm_usb_gadget_handle_interrupts() is only called when
ethernet function is started, at this stage USB events are not managed,
host's enumeration attempts will fail and resulting error like:
    usb 1-1: new high-speed USB device number 50 using xhci_hcd
    usb 1-1: device descriptor read/64, error -110
    usb 1-1: device descriptor read/64, error -110
    usb usb1-port1: attempt power cycle

With this patch the USB controller will only be initialized when ethernet
function is used, in which case USB controller events are handled, so the
host won't see an unresponsive device.

Signed-off-by: Zixun LI <admin at hifiphile.com>
---
 drivers/usb/gadget/ether.c | 15 +++++----------
 1 file changed, 5 insertions(+), 10 deletions(-)

diff --git a/drivers/usb/gadget/ether.c b/drivers/usb/gadget/ether.c
index b7b7bacb00..ed55f12662 100644
--- a/drivers/usb/gadget/ether.c
+++ b/drivers/usb/gadget/ether.c
@@ -2277,6 +2277,9 @@ static int usb_eth_start(struct udevice *udev)
 	packet_received = 0;
 	packet_sent = 0;

+	if (usb_gadget_register_driver(&priv->eth_driver) < 0)
+		goto fail;
+
 	gadget = dev->gadget;
 	usb_gadget_connect(gadget);

@@ -2398,6 +2401,8 @@ static void usb_eth_stop(struct udevice *udev)
 		dm_usb_gadget_handle_interrupts(udev->parent);
 		dev->network_started = 0;
 	}
+
+	usb_gadget_unregister_driver(&priv->eth_driver);
 }

 static int usb_eth_recv(struct udevice *dev, int flags, uchar **packetp)
@@ -2503,15 +2508,6 @@ static int usb_eth_probe(struct udevice *dev)
 	priv->eth_driver.disconnect	= eth_disconnect;
 	priv->eth_driver.suspend	= eth_suspend;
 	priv->eth_driver.resume		= eth_resume;
-	return usb_gadget_register_driver(&priv->eth_driver);
-}
-
-static int usb_eth_remove(struct udevice *dev)
-{
-	struct ether_priv *priv = dev_get_priv(dev);
-
-	usb_gadget_unregister_driver(&priv->eth_driver);
-
 	return 0;
 }

@@ -2526,7 +2522,6 @@ U_BOOT_DRIVER(eth_usb) = {
 	.name	= "usb_ether",
 	.id	= UCLASS_ETH,
 	.probe	= usb_eth_probe,
-	.remove	= usb_eth_remove,
 	.unbind	= usb_eth_unbind,
 	.ops	= &usb_eth_ops,
 	.priv_auto	= sizeof(struct ether_priv),
--
2.45.2