net: usb: cdc_ether: don't spew notifications

JIRA: https://issues.redhat.com/browse/RHEL-52777

commit 2d5c9dd
Author: zhangxiangqian <zhangxiangqian@kylinos.cn>
Date:   Thu Aug 8 17:39:45 2024 +0800

    net: usb: cdc_ether: don't spew notifications
    
    The usbnet_link_change function is not called, if the link has not changed.
    
    ...
    [16913.807393][ 3] cdc_ether 1-2:2.0 enx00e0995fd1ac: kevent 12 may have been dropped
    [16913.822266][ 2] cdc_ether 1-2:2.0 enx00e0995fd1ac: kevent 12 may have been dropped
    [16913.826296][ 2] cdc_ether 1-2:2.0 enx00e0995fd1ac: kevent 11 may have been dropped
    ...
    
    kevent 11 is scheduled too frequently and may affect other event schedules.
    
    Signed-off-by: zhangxiangqian <zhangxiangqian@kylinos.cn>
    Acked-by: Oliver Neukum <oneukum@suse.com>
    Link: https://patch.msgid.link/1723109985-11996-1-git-send-email-zhangxiangqian@kylinos.cn
    Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Signed-off-by: Jose Ignacio Tornos Martinez <jtornosm@redhat.com>

Author: jtornosm

drivers/net/usb/cdc_ether.c

@@ -418,7 +418,8 @@ void usbnet_cdc_status(struct usbnet *dev, struct urb *urb)
 	case USB_CDC_NOTIFY_NETWORK_CONNECTION:
 		netif_dbg(dev, timer, dev->net, "CDC: carrier %s\n",
 			  event->wValue ? "on" : "off");
-		usbnet_link_change(dev, !!event->wValue, 0);
+		if (netif_carrier_ok(dev->net) != !!event->wValue)
+			usbnet_link_change(dev, !!event->wValue, 0);
 		break;
 	case USB_CDC_NOTIFY_SPEED_CHANGE:	/* tx/rx rates */
 		netif_dbg(dev, timer, dev->net, "CDC: speed change (len %d)\n",