Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756210AbaFLQxm (ORCPT ); Thu, 12 Jun 2014 12:53:42 -0400 Received: from arroyo.ext.ti.com ([192.94.94.40]:45613 "EHLO arroyo.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756132AbaFLQxk (ORCPT ); Thu, 12 Jun 2014 12:53:40 -0400 Date: Thu, 12 Jun 2014 11:53:17 -0500 From: Felipe Balbi To: Peter Chen CC: Felipe Balbi , Greg KH , , , Matt Porter Subject: Re: Disable bus's drivers_autoprobe before rootfs has mounted Message-ID: <20140612165317.GD21753@saruman.home> Reply-To: References: <20140611021439.GA25082@shlinux1.ap.freescale.net> <20140611041000.GB15184@kroah.com> <20140611043507.GA30126@saruman.home> <20140611032956.GC25082@shlinux1.ap.freescale.net> <20140611193627.GA19366@saruman.home> <20140612070211.GC18009@shlinux1.ap.freescale.net> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Zs/RYxT/hKAHzkfQ" Content-Disposition: inline In-Reply-To: <20140612070211.GC18009@shlinux1.ap.freescale.net> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --Zs/RYxT/hKAHzkfQ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jun 12, 2014 at 03:02:12PM +0800, Peter Chen wrote: > On Wed, Jun 11, 2014 at 02:36:27PM -0500, Felipe Balbi wrote: > > On Wed, Jun 11, 2014 at 11:29:57AM +0800, Peter Chen wrote: > > > On Tue, Jun 10, 2014 at 11:35:07PM -0500, Felipe Balbi wrote: > > > > Hi, > > > >=20 > > > > On Tue, Jun 10, 2014 at 09:10:00PM -0700, Greg KH wrote: > > > > > > Let's take USB peripheral as an example, there is a device for > > > > > > udc, and a device driver for usb gadget driver, at default, we = want > > > > > > the device to be bound to driver automatically, this is what > > > > > > we have done now. But if there are more than one udcs and gadget > > > > > > drivers (eg one B port for mass storage, another B port for usb= ethernet), > > > > > > the user may want to have specific binding (eg, udc-0 -> mass s= torage, > > > > > > udc-1 -> usb ethernet), so the binding will be established > > > > > > after rootfs has mounted. (This feature is implementing) > > > > >=20 > > > > > Then there better be a way to describe this on the kernel command= line > > > > > (i.e. module paramaters), right? Which is a total mess, why not = just > > > > > not bind anything in this case and let the user pick what they wa= nt? > > > >=20 > > > > you can also blacklist all gadget drivers and manually probe them o= r - > > > > get this - you can refrain from using gadget drivers and use libusb= g to > > > > build the gadget drivers out of raw usb functions, then bind them t= o the > > > > UDC of your liking. > > > >=20 > > >=20 > > > I am just worried if we change the behaviour of using gadget driver, > > > can it be accepted by user? If you think it can be accepted if we can > > > have some docs, we can implement manually binding for gadget driver > > > from now on. > >=20 > > user shouldn't have to deal with direct module insertion/removal (unless > > he's a developer and actually *wants* to do that). Docs are already in > > tree. The entire configfs interface has been documented, it's based on > > those documents that Matt started writing libusbg. > >=20 > > --=20 > > balbi >=20 > Yes, gadget-configfs is a good direction. >=20 > I would like to know your plan for other gadget drivers (g_mass_storage, > g_webcam, etc) they can be built dynamically too. We only provided a version of g_mass_storage in order to avoid regressions. We can't simply remove that driver from the kernel. > All functions will be supported by configfs in future, and current > driver will be deleted? I don't think we will be able to delete legacy drivers, but they're all supported through configfs. I guess only webcam is missing. > - If yes, how to cover the user who still use the old file system? > - If no, which binding way for udc and gadget driver will be used? going forward, we want to stick with configfs. --=20 balbi --Zs/RYxT/hKAHzkfQ Content-Type: application/pgp-signature; name="signature.asc" Content-Description: Digital signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJTmdr9AAoJEIaOsuA1yqREbdcP/0mcP06tnfXYcKLQ/XNQJ8NC usBJR0wvNYsTUKGmge4YJJeOw51iRodbk6WBotOUV5chpdjiUIdAAh004/iWjR0k Up0+KN4uNVGUscuGDuOKPHf62PDOSvkg456TrOzxSLmMZj7LL6KRnKqiGSH4DH7M v8MdgHAb+SuyNDhflc8b4hd72nVRkChczb4iqSviEy7w1OzqfDCFCEoYrRAh5YGe cKppVk29gxqxLDY8N0dpysZr+U8cCi6dkir/M5jITtJIE91/X5JC8E9oAEJemSZO gGjolSGU7gtrGKbhn2U80Nt1qwUj9nbC0aNmChxHovUqS08qKszx1qx/RS3SWqVi OQ+L7TEpQe53slBeoF4rgzLA6UWXC5VtvZyoylWritTRIY/ovaaJaNkJfQP2l7d1 RH4NLRbUj8b+oEd+fOK/hhxZd667BovgyLtUh4kTBd/UT9sdIMrSAWXew+6CeRUX 5g26IamSM9I8+ZvvKPIhF+K8WM93w9SQ/QXYa5iz0NOo/EYR/8whQ5ysEWWNfy/0 r4JqrjFaFlPw1XynHTf0OFyYrE23rXEFTW560ZZq8g45eQgXWLKUQ8OUNqvThZ+7 sQpfj7H3SrKnWu4w+Yv+IYJ56Ud+0SUlD3yf1lOHna94YOQhjIFmB6m6CN/J2xRN yl4OHXjqTSeyK6fTu/Ca =YXmy -----END PGP SIGNATURE----- --Zs/RYxT/hKAHzkfQ-- -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/