[PATCH] usb: gadget: ether: Handle gadget driver registration in start and stop

[Zixun LI]

Hi Mattijs,

On Tue, Aug 6, 2024 at 4:00 PM Mattijs Korpershoek
<mkorpershoek at baylibre.com> wrote:
>
> I'd like to test this on my end as well. Could you please give some
> details on how this has been tested?
>
> A sequence of U-Boot commands would be helpful, for example.

My tests are done on a custom ATMEL SAM9G25 board powered
by USB Gadget port.

Gadget is enabled in the DT:
&usb2 {
status = "okay";
};

usb_ether enabled in board late init:
int board_late_init(void)
{
#ifdef CONFIG_USB_ETHER
usb_ether_init();
#endif
return 0;
}

Without this patch the host will try to enumerate the USB device once
 U-Boot is loaded and result in the error I mentioned.

With this patch USB is connected only when ethernet command, like dhcp
is run, then disconnect when it's finished:
usb 1-1: new high-speed USB device number 91 using xhci_hcd
usb 1-1: New USB device found, idVendor=0000, idProduct=0000, bcdDevice= 3.17
usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=0
usb 1-1: Product: Ethernet Gadget
usb 1-1: Manufacturer: U-Boot
cdc_ether 1-1:1.0 usb0: register 'cdc_ether' at usb-0000:04:00.3-1,
CDC Ethernet Device, de:ad:be:ef:00:00
cdc_ether 1-1:1.0 enp4s0f3u1: renamed from usb0
gadget0: port 1(enp4s0f3u1) entered blocking state
gadget0: port 1(enp4s0f3u1) entered disabled state
cdc_ether 1-1:1.0 enp4s0f3u1: entered allmulticast mode
cdc_ether 1-1:1.0 enp4s0f3u1: entered promiscuous mode
gadget0: port 1(enp4s0f3u1) entered blocking state
gadget0: port 1(enp4s0f3u1) entered forwarding state
usb 1-1: USB disconnect, device number 91