[PATCH] net: usb: cdc_ether: don't spew notifications

From: zhangxiangqian
Date: Thu Aug 08 2024 - 05:40:59 EST


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@xxxxxxxxxx>
---
drivers/net/usb/cdc_ether.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/usb/cdc_ether.c b/drivers/net/usb/cdc_ether.c
index 6d61052..a646923 100644
--- 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",
--
2.7.4