Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754593Ab3JBSeT (ORCPT ); Wed, 2 Oct 2013 14:34:19 -0400 Received: from [216.32.180.16] ([216.32.180.16]:37745 "EHLO va3outboundpool.messaging.microsoft.com" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1754336Ab3JBSeS (ORCPT ); Wed, 2 Oct 2013 14:34:18 -0400 X-Forefront-Antispam-Report: CIP:70.37.183.190;KIP:(null);UIP:(null);IPV:NLI;H:mail.freescale.net;RD:none;EFVD:NLI X-SpamScore: -7 X-BigFish: VS-7(zz98dI9371I936eI542I1432I168aJzz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzz1de098h1de097h8275dhz2dh2a8h839h93fhd24hf0ah1288h12a5h12a9h12bdh137ah139eh13b6h1441h1504h1537h162dh1631h1758h1898h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e23h1fe8h1ff5h1155h) Message-ID: <1380738758.12932.43.camel@snotra.buserror.net> Subject: Re: RFC: (re-)binding the VFIO platform driver to a platform device From: Scott Wood To: Yoder Stuart-B08248 CC: Christoffer Dall , Alex Williamson , Kim Phillips , "gregkh@linuxfoundation.org" , "linux-kernel@vger.kernel.org" , "a.motakis@virtualopensystems.com" , "agraf@suse.de" , Wood Scott-B07421 , Sethi Varun-B16395 , Bhushan Bharat-R65777 , "peter.maydell@linaro.org" , "santosh.shukla@linaro.org" , "kvm@vger.kernel.org" Date: Wed, 2 Oct 2013 13:32:38 -0500 In-Reply-To: <9F6FE96B71CF29479FF1CDC8046E15036D405D@039-SN1MPN1-003.039d.mgd.msft.net> References: <20131001133831.6e46e8e00e09d5d9079fde57@linaro.org> <20131001200054.GA27330@kroah.com> <20131001170244.ff4fb81d9a7a09598c4c6247@linaro.org> <20131002015355.GD63102@lvm> <1380681356.14271.57.camel@ul30vt.home> <20131002151413.GG63102@lvm> <9F6FE96B71CF29479FF1CDC8046E15036D405D@039-SN1MPN1-003.039d.mgd.msft.net> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.6.4-0ubuntu1 MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-OriginatorOrg: freescale.com X-FOPE-CONNECTOR: Id%0$Dn%*$RO%0$TLS%0$FQDN%$TlsDn% Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1925 Lines: 44 On Wed, 2013-10-02 at 13:25 -0500, Yoder Stuart-B08248 wrote: > > > -----Original Message----- > > From: Christoffer Dall [mailto:christoffer.dall@linaro.org] > > Sent: Wednesday, October 02, 2013 10:14 AM > > To: Alex Williamson > > Cc: Kim Phillips; gregkh@linuxfoundation.org; linux- > > kernel@vger.kernel.org; a.motakis@virtualopensystems.com; agraf@suse.de; > > Yoder Stuart-B08248; Wood Scott-B07421; Sethi Varun-B16395; Bhushan > > Bharat-R65777; peter.maydell@linaro.org; santosh.shukla@linaro.org; > > kvm@vger.kernel.org > > Subject: Re: RFC: (re-)binding the VFIO platform driver to a platform > > device > > > > Wouldn't a sysfs file to add compatibility strings to the vfio-platform > > driver make driver_match_device return true and make everyone happy? > > I had a similar thought. Why can't we do something like: > > echo "fsl,i2c" > /sys/bus/platform/drivers/vfio-platform/new_compatible > echo 12ce0000.i2c > /sys/bus/platform/drivers/vfio-platform/bind > > The first steps tell vfio-platform to register itself to handle > "fsl,i2c" compatible devices. The second step does the bind. Needing to specify the compatible is hacky (we already know what device we want to bind; why do we need to scrounge up more information than that, and add a new sysfs interface for extending compatible matches, and a more flexible data structure to back that up?), and is racy on buses that can hotplug (which driver gets the new device?). What's wrong with a non-vfio-specific flag that a driver can set, that indicates that the driver is willing to try to bind to any device on the bus if explicitly requested via the existing sysfs bind mechanism? -Scott -- 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/