Re: [PATCH 4/4] USB: gadget: Add a new bus for gadgets

From: Alan Stern
Date: Mon May 09 2022 - 10:15:08 EST


On Mon, May 09, 2022 at 09:46:25AM +0200, Geert Uytterhoeven wrote:
> > Geert:
> >
> > Can you test the patch below? It ought to fix the problem (although it
>
> Thanks!
>
> root@h3-salvator-xs:~# ls -l /sys/bus/gadget/devices/
> total 0
> lrwxrwxrwx 1 root root 0 Feb 14 2019 gadget.0 ->
> ../../../devices/platform/soc/e659c000.usb/gadget.0
> lrwxrwxrwx 1 root root 0 Feb 14 2019 gadget.1 ->
> ../../../devices/platform/soc/ee020000.usb/gadget.1
> lrwxrwxrwx 1 root root 0 Feb 14 2019 gadget.2 ->
> ../../../devices/platform/soc/e6590000.usb/gadget.2
>
> Tested-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
>
> LGTM, so
> Reviewed-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>

Thanks!

> > might end up causing other problems down the line...)
>
> Can you please elaborate? I'm not too familiar with UBS gadgets.

I was concerned about the fact that changing the name of a file,
directory, or symbolic link in sysfs means changing a user API, and so
it might cause some existing programs to fail. That would be a
regression.

Perhaps the best way to work around the problem is to leave the name set
to "gadget" if the ID number is 0, while adding the ID number on to the
name if the value is > 0. What do you think?

Alan Stern