Re: [PATCH] usb: gadget: u_ether: Re-attach netif device to mirror detachment

[Ferry Toth <fntoth@gmail.com>]

Hi,

Op 18-12-2023 om 17:45 schreef Richard Acayan:
> In 6.7-rc1, there was a netif_device_detach call added to the
> gether_disconnect function. This clears the __LINK_STATE_PRESENT bit of
> the netif device and suppresses pings (ICMP messages) and TCP connection
> requests from the connected host. If userspace temporarily disconnects
> the gadget, such as by temporarily removing configuration in the gadget
> configfs interface, network activity should continue to be processed
> when the gadget is re-connected. Mirror the netif_device_detach call
> with a netif_device_attach call in gether_connect to fix re-connecting
> gadgets.
> 
> Link: https://gitlab.com/postmarketOS/pmaports/-/tree/6002e51b7090aeeb42947e0ca7ec22278d7227d0/main/postmarketos-base-ui/rootfs-usr-lib-NetworkManager-dispatcher.d-50-tethering.sh
> Fixes: f49449fbc21e ("usb: gadget: u_ether: Replace netif_stop_queue with netif_device_detach")
> Signed-off-by: Richard Acayan <mailingradian@gmail.com>
> ---
>   drivers/usb/gadget/function/u_ether.c | 2 ++
>   1 file changed, 2 insertions(+)
> 
> diff --git a/drivers/usb/gadget/function/u_ether.c b/drivers/usb/gadget/function/u_ether.c
> index 9d1c40c152d8..3c5a6f6ac341 100644
> --- a/drivers/usb/gadget/function/u_ether.c
> +++ b/drivers/usb/gadget/function/u_ether.c
> @@ -1163,6 +1163,8 @@ struct net_device *gether_connect(struct gether *link)
>   		if (netif_running(dev->net))
>   			eth_start(dev, GFP_ATOMIC);
>   
> +		netif_device_attach(dev->net);
> +
>   	/* on error, disable any endpoints  */
>   	} else {
>   		(void) usb_ep_disable(link->out_ep);
This works mrfld (Intel Edison Arduino) using configfs with v6.7.0. 
Tested using `iperf3 -s` on mrfld,
iperf3 --bidir -c edison-usb
[ ID][Role] Interval           Transfer     Bitrate         Retr
[  5][TX-C]   0.00-10.00  sec   130 MBytes   109 Mbits/sec    0 
    sender
[  5][TX-C]   0.00-9.99   sec   129 MBytes   108 Mbits/sec 
    receiver
[  7][RX-C]   0.00-10.00  sec   167 MBytes   140 Mbits/sec    0 
    sender
[  7][RX-C]   0.00-9.99   sec   166 MBytes   139 Mbits/sec 
    receiver

and
iperf3 -c edison-usb
[  5]   0.00-10.00  sec   247 MBytes   207 Mbits/sec    0             sender
[  5]   0.00-9.99   sec   246 MBytes   206 Mbits/sec 
receiver


Tested-by: Ferry Toth <fntoth@gmail.com> [mrfld]