[PATCH] cdc-ether: divorce initialisation with a filter reset and a generic method

Some devices need their multicast filter reset but others are crashed by that.
So the methods need to be separated.

Signed-off-by: Oliver Neukum <oneukum@suse.com>
Reported-by: "Ridgway, Keith" <redacted>
---
 drivers/net/usb/cdc_ether.c | 34 +++++++++++++++++++++++++---------
 1 file changed, 25 insertions(+), 9 deletions(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index f3ae88fdf332..70d823043803 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c

@@ -310,6 +310,26 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 		return -ENODEV;
 	}
 
+	return 0;
+
+bad_desc:
+	dev_info(&dev->udev->dev, "bad CDC descriptors\n");
+	return -ENODEV;
+}
+EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);
+
+
+/* like usbnet_generic_cdc_bind() but handles filter initialization
+ * correctly
+ */
+int usbnet_ether_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
+{
+	int rv;
+
+	rv = usbnet_generic_cdc_bind(dev, intf);
+	if (rv < 0)
+		goto bail_out;
+
 	/* Some devices don't initialise properly. In particular
 	 * the packet filter is not reset. There are devices that
 	 * don't do reset all the way. So the packet filter should

@@ -317,13 +337,10 @@ int usbnet_generic_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 	 */
 	usbnet_cdc_update_filter(dev);
 
-	return 0;
-
-bad_desc:
-	dev_info(&dev->udev->dev, "bad CDC descriptors\n");
-	return -ENODEV;
+bail_out:
+	return rv;
 }
-EXPORT_SYMBOL_GPL(usbnet_generic_cdc_bind);
+EXPORT_SYMBOL_GPL(usbnet_ether_cdc_bind);
 
 void usbnet_cdc_unbind(struct usbnet *dev, struct usb_interface *intf)
 {

@@ -417,7 +434,7 @@ int usbnet_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 	BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data)
 			< sizeof(struct cdc_state)));
 
-	status = usbnet_generic_cdc_bind(dev, intf);
+	status = usbnet_ether_cdc_bind(dev, intf);
 	if (status < 0)
 		return status;
 

@@ -472,7 +489,6 @@ static void usbnet_cdc_zte_status(struct usbnet *dev, struct urb *urb)
 
 	if (urb->actual_length < sizeof(*event))
 		return;
-
 	event = urb->transfer_buffer;
 
 	if (event->bNotificationType != USB_CDC_NOTIFY_NETWORK_CONNECTION) {

@@ -493,7 +509,7 @@ static void usbnet_cdc_zte_status(struct usbnet *dev, struct urb *urb)
 static const struct driver_info	cdc_info = {
 	.description =	"CDC Ethernet Device",
 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT,
-	.bind =		usbnet_cdc_bind,
+	.bind =		usbnet_ether_cdc_bind,
 	.unbind =	usbnet_cdc_unbind,
 	.status =	usbnet_cdc_status,
 	.set_rx_mode =	usbnet_cdc_update_filter,

-- 
2.12.0

Oliver Neukum [off-list ref] writes:

I didn't quite get this.  You change the call in usbnet_cdc_bind() from
usbnet_generic_cdc_bind() to usbnet_ether_cdc_bind(), which I believe is
fine.  But then you update the .bind hook to point to usbnet_ether_cdc_bind.
Why?  The only effect I can see is that usbnet_get_ethernet_addr() is
skipped. That can't be correct?


Bjørn

Am Donnerstag, den 18.05.2017, 12:09 +0200 schrieb Bjørn Mork:

Oliver Neukum [off-list ref] writes:

quoted

@@ -417,7 +434,7 @@ int usbnet_cdc_bind(struct usbnet *dev, struct usb_interface *intf)
 	BUILD_BUG_ON((sizeof(((struct usbnet *)0)->data)
 			< sizeof(struct cdc_state)));
 
-	status = usbnet_generic_cdc_bind(dev, intf);
+	status = usbnet_ether_cdc_bind(dev, intf);
 	if (status < 0)
 		return status;
 

@@ -472,7 +489,6 @@ static void usbnet_cdc_zte_status(struct usbnet *dev, struct urb *urb)
 
 	if (urb->actual_length < sizeof(*event))
 		return;
-
 	event = urb->transfer_buffer;
 
 	if (event->bNotificationType != USB_CDC_NOTIFY_NETWORK_CONNECTION) {

@@ -493,7 +509,7 @@ static void usbnet_cdc_zte_status(struct usbnet *dev, struct urb *urb)
 static const struct driver_info	cdc_info = {
 	.description =	"CDC Ethernet Device",
 	.flags =	FLAG_ETHER | FLAG_POINTTOPOINT,
-	.bind =		usbnet_cdc_bind,
+	.bind =		usbnet_ether_cdc_bind,
 	.unbind =	usbnet_cdc_unbind,
 	.status =	usbnet_cdc_status,
 	.set_rx_mode =	usbnet_cdc_update_filter,

I didn't quite get this.  You change the call in usbnet_cdc_bind() from
usbnet_generic_cdc_bind() to usbnet_ether_cdc_bind(), which I believe is
fine.  But then you update the .bind hook to point to usbnet_ether_cdc_bind.
Why?  The only effect I can see is that usbnet_get_ethernet_addr() is
skipped. That can't be correct?

You are right. I am an idiot. I wanted to target RNDIS and missed totally.
Thanks.

Dave please trash the patch.

	Regards
		Oliver