On Mon, Mar 16, 2020 at 09:05:12AM +0200, Felipe Balbi wrote:
>
> Hi,
>
> Masahiro Yamada <masahiroy@xxxxxxxxxx> writes:
> > drivers/usb/gadget/legacy/Kconfig creates a 'choice' inside another
> > 'choice'.
> >
> > The outer choice: line 17 "USB Gadget precomposed configurations"
> > The inner choice: line 484 "EHCI Debug Device mode"
> >
> > I wondered why the whole legacy gadget drivers reside in such a big
> > choice block.
> >
> > This dates back to 2003, "[PATCH] USB: fix for multiple definition of
> > `usb_gadget_get_string'". [1]
> >
> > At that time, the global function, usb_gadget_get_string(), was linked
> > into multiple drivers. That was why only one driver was able to become
> > built-in at the same time.
> >
> > Later, commit a84d9e5361bc ("usb: gadget: start with libcomposite")
> > moved usb_gadget_get_string() to a separate module, libcomposite.ko
> > instead of including usbstring.c from multiple modules.
> >
> > More and more refactoring was done, and after commit 1bcce939478f
> > ("usb: gadget: multi: convert to new interface of f_mass_storage"),
> > you can link multiple gadget drivers into vmlinux without causing
> > multiple definition error.
> >
> > This is the only user of the nested choice structure ever. Removing
> > this mess will make some Kconfig cleanups possible.
> >
> > [1]: https://git.kernel.org/pub/scm/linux/kernel/git/history/history.git/commit/?id=fee4cf49a81381e072c063571d1aadbb29207408
> >
> > Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
>
> Greg, if you want to pick this for v5.7, please go ahead:
>
> Acked-by: Felipe Balbi <balbi@xxxxxxxxxx>
Thanks, will take it later today.
greg k-h
