Hi, On Tue, Jun 7, 2016 at 11:06 AM, Peter Chen <peter.chen@xxxxxxx> wrote: > > >>-----Original Message----- >>From: linux-usb-owner@xxxxxxxxxxxxxxx [mailto:linux-usb-owner@xxxxxxxxxxxxxxx] >>On Behalf Of Krzysztof Opasiak >>Sent: Tuesday, June 07, 2016 3:46 PM >>To: Peter Chen <hzpeterchen@xxxxxxxxx> >>Cc: Krzysztof Opasiak <k.opasiak@xxxxxxxxxxx>; balbi@xxxxxxxxxx; Greg Kroah- >>Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>; Andrzej Pietrasiewicz >><andrzej.p@xxxxxxxxxxx>; Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>; >>linux-usb@xxxxxxxxxxxxxxx >>Subject: Re: [RFC][PATCH] usb: gadget: Allow to build both USB functions and >>legacy gadgets >> >>Hi, >> >>On Tue, Jun 7, 2016 at 3:27 AM, Peter Chen <hzpeterchen@xxxxxxxxx> wrote: >>> On Mon, Jun 06, 2016 at 09:40:33PM +0200, Krzysztof Opasiak wrote: >>>> Currently it is possible to build in some subset of usb functions >>>> *OR* some gadget module. This is limited only by Kconfig not any >>>> functionality. >>>> >>>> This patch removes this limitation. With this patch it is possible to >>>> set up all build combinations: >>>> 1) Multiple gadgets build in >>> >>> If that, what the user will expect if choosing multiple gadgets? >>> Eg, if he chooses g_ncm and g_mass_storage, will he expect his udc has >>> both mass_storage and ncm function, but it is not the fact, only the >>> first gadget function will work. >>> >> >>Not exactly one. You may build in multiple modules and use those multiple modules if >>you have multiple udcs. >> > > My concern is: with your patch, the user may get unexpected results if he builds in > multiple gadgets for this single udc. At current code, the user can't do that, then he will > not get unexpected results. How do you consider that? > That's true but even without this patch user may build multiple gadgets as a modules. Even more, after commit (855ed04 "usb: gadget: udc-core: independent registration of gadgets and gadget drivers") it is possible to load multiple gadget modules even if we have one UDC. So why would you like to disallow building in multiple gadgets if user can build them as a modules and simply load? If you concern about order of probing and binding to udc, I think that we can add udc module param to all legacy gadgets so user can specify in kernel cmd line where each gadget should be bound. -- Best regards, Krzysztof Opasiak -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
