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>

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 6d61052353f078e41cdb53b2fcb07bf900a4768c..a6469235d904e7d87eb7162f3c83b9ad87971a34 100644 (file)
--- a/drivers/net/usb/cdc_ether.c
+++ b/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",