From: Maciej Żenczykowski maze@google.com
[ Upstream commit c1a3d4067309451e68c33dbd356032549cc0bd8e ]
This is meant to make the host side cdc_ncm interface consistently named just like the older CDC protocols: cdc_ether & cdc_ecm (and even rndis_host), which all use 'FLAG_ETHER | FLAG_POINTTOPOINT'.
include/linux/usb/usbnet.h: #define FLAG_ETHER 0x0020 /* maybe use "eth%d" names */ #define FLAG_WLAN 0x0080 /* use "wlan%d" names */ #define FLAG_WWAN 0x0400 /* use "wwan%d" names */ #define FLAG_POINTTOPOINT 0x1000 /* possibly use "usb%d" names */
drivers/net/usb/usbnet.c @ line 1711: strcpy (net->name, "usb%d"); ... // heuristic: "usb%d" for links we know are two-host, // else "eth%d" when there's reasonable doubt. userspace // can rename the link if it knows better. if ((dev->driver_info->flags & FLAG_ETHER) != 0 && ((dev->driver_info->flags & FLAG_POINTTOPOINT) == 0 || (net->dev_addr [0] & 0x02) == 0)) strcpy (net->name, "eth%d"); /* WLAN devices should always be named "wlan%d" */ if ((dev->driver_info->flags & FLAG_WLAN) != 0) strcpy(net->name, "wlan%d"); /* WWAN devices should always be named "wwan%d" */ if ((dev->driver_info->flags & FLAG_WWAN) != 0) strcpy(net->name, "wwan%d");
So by using ETHER | POINTTOPOINT the interface naming is either usb%d or eth%d based on the global uniqueness of the mac address of the device.
Without this 2.5gbps ethernet dongles which all seem to use the cdc_ncm driver end up being called usb%d instead of eth%d even though they're definitely not two-host. (All 1gbps & 5gbps ethernet usb dongles I've tested don't hit this problem due to use of different drivers, primarily r8152 and aqc111)
Fixes tag is based purely on git blame, and is really just here to make sure this hits LTS branches newer than v4.5.
Cc: Lorenzo Colitti lorenzo@google.com Fixes: 4d06dd537f95 ("cdc_ncm: do not call usbnet_link_change from cdc_ncm_bind") Signed-off-by: Maciej Żenczykowski maze@google.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/usb/cdc_ncm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/net/usb/cdc_ncm.c b/drivers/net/usb/cdc_ncm.c index 8acf30115428..dc3d84b43e4e 100644 --- a/drivers/net/usb/cdc_ncm.c +++ b/drivers/net/usb/cdc_ncm.c @@ -1902,7 +1902,7 @@ static void cdc_ncm_status(struct usbnet *dev, struct urb *urb) static const struct driver_info cdc_ncm_info = { .description = "CDC NCM", .flags = FLAG_POINTTOPOINT | FLAG_NO_SETINT | FLAG_MULTI_PACKET - | FLAG_LINK_INTR, + | FLAG_LINK_INTR | FLAG_ETHER, .bind = cdc_ncm_bind, .unbind = cdc_ncm_unbind, .manage_power = usbnet_manage_power,