From: Bart Van Assche <Bart.VanAssche@wdc.com>
To: "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        "arnd@arndb.de" <arnd@arndb.de>, "balbi@kernel.org" <balbi@kernel.org>
CC: "romain.izard.pro@gmail.com" <romain.izard.pro@gmail.com>,
        "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "linux-usb@vger.kernel.org" <linux-usb@vger.kernel.org>,
        "linux-media@vger.kernel.org" <linux-media@vger.kernel.org>,
        "mchehab@kernel.org" <mchehab@kernel.org>,
        "ruslan.bilovol@gmail.com" <ruslan.bilovol@gmail.com>,
        "hare@suse.com" <hare@suse.com>,
        "cascardo@cascardo.eti.br" <cascardo@cascardo.eti.br>
Subject: Re: [PATCH 1/2] usb: gadget: restore tristate-choice for legacy
 gadgets
Thread-Topic: [PATCH 1/2] usb: gadget: restore tristate-choice for legacy
 gadgets
Thread-Index: AQHTcnOEzlKM72dCuUOdAfpC+lmT+qM+T+WA
Date: Mon, 11 Dec 2017 16:09:20 +0000
Message-ID: <1513008559.2747.0.camel@wdc.com>
References: <20171211113048.3514863-1-arnd@arndb.de>
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On Mon, 2017-12-11 at 12:30 +0100, Arnd Bergmann wrote:
> One patch that was meant as a cleanup apparently did more than it intended,
> allowing all combinations of legacy gadget drivers to be built into the
> kernel, and leaving an empty 'choice' statement behind:
> 
> drivers/usb/gadget/Kconfig:487:warning: choice default symbol 'USB_ETH' is not contained in the choice
> 
> The description of commit 7a9618a22aad ("usb: gadget: allow to enable legacy
> drivers without USB_ETH") was a bit cryptic, as it did not change the
> behavior of USB_ETH other than allowing it to be built into the kernel
> alongside other legacy gadgets, which is not a valid configuration.
> 
> As Felipe explained in the description for commit bc49d1d17dcf ("usb:
> gadget: don't couple configfs to legacy gadgets"), the configfs based
> gadgets can be freely configured as loadable modules or built-in
> drivers, but the legacy gadgets can only be modules if there is more
> than one of them, so we require the 'choice' statement here.
> 
> This leaves the added USB_GADGET_LEGACY menuconfig symbol in place,
> but then restores the 'choice' below it, so we can enforce the
> single-legacy-gadget rule as before.

Hello Arnd,

A discussion is ongoing about whether or not commit 7a9618a22aad should be reverted.
Please drop this patch until a conclusion has been reached.

Thanks,

Bart.