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Commit c1b187a8 authored by Ondrej Zary's avatar Ondrej Zary Committed by Greg Kroah-Hartman
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cx82310_eth: re-enable ethernet mode after router reboot 



[ Upstream commit ca139d76b0d9e59d18f2d2ec8f0d81b82acd6808 ]

When the router is rebooted without a power cycle, the USB device
remains connected but its configuration is reset. This results in
a non-working ethernet connection with messages like this in syslog:
	usb 2-2: RX packet too long: 65535 B

Re-enable ethernet mode when receiving a packet with invalid size of
0xffff.

Signed-off-by: default avatarOndrej Zary <linux@zary.sk>
Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
Stable-dep-of: bab8eb0dd4cb ("usbnet: modern method to get random MAC")
Signed-off-by: default avatarSasha Levin <sashal@kernel.org>
parent 6f9fdf58

drivers/net/usb/cx82310_eth.c

+44 −6
Original line number Diff line number Diff line
@@ -40,6 +40,11 @@ enum cx82310_status { 
#define CX82310_MTU	1514

#define CMD_EP		0x01



struct cx82310_priv {

	struct work_struct reenable_work;

	struct usbnet *dev;

};



/*

 * execute control command

 *  - optionally send some data (command parameters)
@@ -115,6 +120,23 @@ static int cx82310_cmd(struct usbnet *dev, enum cx82310_cmd cmd, bool reply, 
	return ret;

}



static int cx82310_enable_ethernet(struct usbnet *dev)

{

	int ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);



	if (ret)

		netdev_err(dev->net, "unable to enable ethernet mode: %d\n",

			   ret);

	return ret;

}



static void cx82310_reenable_work(struct work_struct *work)

{

	struct cx82310_priv *priv = container_of(work, struct cx82310_priv,

						 reenable_work);

	cx82310_enable_ethernet(priv->dev);

}



#define partial_len	data[0]		/* length of partial packet data */

#define partial_rem	data[1]		/* remaining (missing) data length */

#define partial_data	data[2]		/* partial packet data */
@@ -126,6 +148,7 @@ static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf) 
	struct usb_device *udev = dev->udev;

	u8 link[3];

	int timeout = 50;

	struct cx82310_priv *priv;



	/* avoid ADSL modems - continue only if iProduct is "USB NET CARD" */

	if (usb_string(udev, udev->descriptor.iProduct, buf, sizeof(buf)) > 0
@@ -152,6 +175,15 @@ static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf) 
	if (!dev->partial_data)

		return -ENOMEM;



	priv = kzalloc(sizeof(*priv), GFP_KERNEL);

	if (!priv) {

		ret = -ENOMEM;

		goto err_partial;

	}

	dev->driver_priv = priv;

	INIT_WORK(&priv->reenable_work, cx82310_reenable_work);

	priv->dev = dev;



	/* wait for firmware to become ready (indicated by the link being up) */

	while (--timeout) {

		ret = cx82310_cmd(dev, CMD_GET_LINK_STATUS, true, NULL, 0,
@@ -168,12 +200,8 @@ static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf) 
	}



	/* enable ethernet mode (?) */

	ret = cx82310_cmd(dev, CMD_ETHERNET_MODE, true, "\x01", 1, NULL, 0);

	if (ret) {

		dev_err(&udev->dev, "unable to enable ethernet mode: %d\n",

			ret);

	if (cx82310_enable_ethernet(dev))

		goto err;

	}



	/* get the MAC address */

	ret = cx82310_cmd(dev, CMD_GET_MAC_ADDR, true, NULL, 0,
@@ -190,13 +218,19 @@ static int cx82310_bind(struct usbnet *dev, struct usb_interface *intf) 


	return 0;

err:

	kfree(dev->driver_priv);

err_partial:

	kfree((void *)dev->partial_data);

	return ret;

}



static void cx82310_unbind(struct usbnet *dev, struct usb_interface *intf)

{

	struct cx82310_priv *priv = dev->driver_priv;



	kfree((void *)dev->partial_data);

	cancel_work_sync(&priv->reenable_work);

	kfree(dev->driver_priv);

}



/*
@@ -211,6 +245,7 @@ static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 
{

	int len;

	struct sk_buff *skb2;

	struct cx82310_priv *priv = dev->driver_priv;



	/*

	 * If the last skb ended with an incomplete packet, this skb contains
@@ -245,7 +280,10 @@ static int cx82310_rx_fixup(struct usbnet *dev, struct sk_buff *skb) 
			break;

		}



		if (len > CX82310_MTU) {

		if (len == 0xffff) {

			netdev_info(dev->net, "router was rebooted, re-enabling ethernet mode");

			schedule_work(&priv->reenable_work);

		} else if (len > CX82310_MTU) {

			dev_err(&dev->udev->dev, "RX packet too long: %d B\n",

				len);

			return 0;