cdc-ether: implement MULTICAST flag on the device

Olivier having laid the groundwork this patch transmits the
multicast flag to the device to save some bus traffic.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 10 insertions, 9 deletions

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index d3920b54a92c..9311a08565be 100644
--- a/drivers/net/usb/cdc_ether.c
+++ b/drivers/net/usb/cdc_ether.c
@@ -71,18 +71,19 @@ static void usbnet_cdc_update_filter(struct usbnet *dev)
 {
         struct cdc_state        *info = (void *) &dev->data;
         struct usb_interface    *intf = info->control;
+        struct net_device       *net = dev->net;
 
-        u16 cdc_filter =
-            USB_CDC_PACKET_TYPE_ALL_MULTICAST | USB_CDC_PACKET_TYPE_DIRECTED |
-            USB_CDC_PACKET_TYPE_BROADCAST;
+        u16 cdc_filter = USB_CDC_PACKET_TYPE_DIRECTED
+                        | USB_CDC_PACKET_TYPE_BROADCAST;
 
-        if (dev->net->flags & IFF_PROMISC)
-                cdc_filter |= USB_CDC_PACKET_TYPE_PROMISCUOUS;
-
-        /* FIXME cdc-ether has some multicast code too, though it complains
-         * in routine cases.  info->ether describes the multicast support.
-         * Implement that here, manipulating the cdc filter as needed.
+        /* filtering on the device is an optional feature and not worth
+         * the hassle so we just roughly care about snooping and if any
+         * multicast is requested, we take every multicast
          */
+        if (net->flags & IFF_PROMISC)
+                cdc_filter |= USB_CDC_PACKET_TYPE_PROMISCUOUS;
+        if (!netdev_mc_empty(net) || (net->flags & IFF_ALLMULTI))
+                cdc_filter |= USB_CDC_PACKET_TYPE_ALL_MULTICAST;
 
         usb_control_msg(dev->udev,
                         usb_sndctrlpipe(dev->udev, 0),