Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755050Ab3JITof (ORCPT ); Wed, 9 Oct 2013 15:44:35 -0400 Received: from co1ehsobe003.messaging.microsoft.com ([216.32.180.186]:6798 "EHLO co1outboundpool.messaging.microsoft.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752090Ab3JITod (ORCPT ); Wed, 9 Oct 2013 15:44:33 -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: -4 X-BigFish: VS-4(zz98dI9371I936eI542I1432Izz1f42h208ch1ee6h1de0h1fdah2073h1202h1e76h1d1ah1d2ah1fc6hzz1de098h1de097h8275dhz2dh2a8h839h8e2h8e3h93fhd25hf0ah1288h12a5h12a9h12bdh137ah13b6h1441h1504h1537h153bh15d0h162dh1631h1758h18e1h1946h19b5h1ad9h1b0ah1b2fh1fb3h1d0ch1d2eh1d3fh1dfeh1dffh1e1dh1fe8h1ff5hbe9i1155h) From: Yoder Stuart-B08248 To: Wood Scott-B07421 CC: Kim Phillips , Christoffer Dall , Alex Williamson , "linux-kernel@vger.kernel.org" , "a.motakis@virtualopensystems.com" , "agraf@suse.de" , Sethi Varun-B16395 , Bhushan Bharat-R65777 , "peter.maydell@linaro.org" , "santosh.shukla@linaro.org" , "kvm@vger.kernel.org" , "gregkh@linuxfoundation.org" Subject: RE: RFC: (re-)binding the VFIO platform driver to a platform device Thread-Topic: RFC: (re-)binding the VFIO platform driver to a platform device Thread-Index: AQHOvtVyiXjaos/F7ECAilSa5Xx4A5ngRDQAgAAiCgCAAECXgIAAC74AgADT3ICAADSaMIAAAtYAgAADCQCAAB/ggIAACLGAgAACMICAAAU8gIAAIuWAgAE8pICAAAXnAIAABMAAgAAWmACACVE7IIAACQSAgAAB3+A= Date: Wed, 9 Oct 2013 19:44:28 +0000 Message-ID: <9F6FE96B71CF29479FF1CDC8046E15036DDAB4@039-SN1MPN1-002.039d.mgd.msft.net> References: <1380738758.12932.43.camel@snotra.buserror.net> <20131002184330.GC5108@cbox> <20131002203735.GA10871@kroah.com> <1380748121.12932.89.camel@snotra.buserror.net> <20131002211631.GA11914@kroah.com> <1380749715.12932.109.camel@snotra.buserror.net> <20131002234009.GA27714@kroah.com> <1380825207.12932.151.camel@snotra.buserror.net> <20131003185434.GA26123@kroah.com> <1380827494.12932.161.camel@snotra.buserror.net> <20131003203226.GB27336@kroah.com> <9F6FE96B71CF29479FF1CDC8046E15036DDA62@039-SN1MPN1-002.039d.mgd.msft.net> <1381346507.7979.334.camel@snotra.buserror.net> In-Reply-To: <1381346507.7979.334.camel@snotra.buserror.net> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.82.120.14] Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 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-Transfer-Encoding: 8bit X-MIME-Autoconverted: from base64 to 8bit by mail.home.local id r99Jicpb014798 Content-Length: 3641 Lines: 93 > -----Original Message----- > From: Wood Scott-B07421 > Sent: Wednesday, October 09, 2013 2:22 PM > To: Yoder Stuart-B08248 > Cc: Wood Scott-B07421; Kim Phillips; Christoffer Dall; Alex Williamson; > linux-kernel@vger.kernel.org; a.motakis@virtualopensystems.com; > agraf@suse.de; Sethi Varun-B16395; Bhushan Bharat-R65777; > peter.maydell@linaro.org; santosh.shukla@linaro.org; kvm@vger.kernel.org; > gregkh@linuxfoundation.org > Subject: Re: RFC: (re-)binding the VFIO platform driver to a platform > device > > On Wed, 2013-10-09 at 14:02 -0500, Yoder Stuart-B08248 wrote: > > Have been thinking about this issue some more. As Scott mentioned, > > 'wildcard' matching for a driver can be fairly done in the platform > > bus driver. We could add a new flag to the platform driver struct: > > > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > > index 4f8bef3..4d6cf14 100644 > > --- a/drivers/base/platform.c > > +++ b/drivers/base/platform.c > > @@ -727,6 +727,10 @@ static int platform_match(struct device *dev, > struct device_driver *drv) > > struct platform_device *pdev = to_platform_device(dev); > > struct platform_driver *pdrv = to_platform_driver(drv); > > > > + /* the driver matches any device */ > > + if (pdrv->match_any) > > + return 1; > > + > > /* Attempt an OF style match first */ > > if (of_driver_match_device(dev, drv)) > > return 1; > > > > However, the more problematic issue is that a bus driver has no way to > > differentiate from an explicit bind request via sysfs and a bind that > > happened through bus probing. > > Again, I think the wildcard match should be orthogonal to "don't bind by > default" as far as the mechanism goes. > > There's already a "bool suppress_bind_attrs" to prevent sysfs > bind/unbind. I suggested a similar flag to mean the oppsosite -- bind > *only* through sysfs. Greg KH was skeptical and wanted to see a patch > before any further discussion. Ah, think I understand now...yes that works as well, and would be less intrustive. So are you writing a patch? :) It would be something like this, right? diff --git a/drivers/base/dd.c b/drivers/base/dd.c index 35fa368..c9a61ea 100644 --- a/drivers/base/dd.c +++ b/drivers/base/dd.c @@ -389,7 +389,7 @@ static int __device_attach(struct device_driver *drv, void *data) { struct device *dev = data; - if (!driver_match_device(drv, dev)) + if (!drv->explicit_bind_only && !driver_match_device(drv, dev)) return 0; return driver_probe_device(drv, dev); @@ -450,7 +450,7 @@ static int __driver_attach(struct device *dev, void *data) * is an error. */ - if (!driver_match_device(drv, dev)) + if (!drv->explicit_bind_only && !driver_match_device(drv, dev)) return 0; if (dev->parent) /* Needed for USB */ diff --git a/include/linux/device.h b/include/linux/device.h index 2a9d6ed..f2be980 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -236,6 +236,7 @@ struct device_driver { const char *mod_name; /* used for built-in modules */ bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ + bool explicit_bind_only; /* enables bind/unbind via sysfs only */ const struct of_device_id *of_match_table; const struct acpi_device_id *acpi_match_table; Stuart ????{.n?+???????+%?????ݶ??w??{.n?+????{??G?????{ay?ʇڙ?,j??f???h?????????z_??(?階?ݢj"???m??????G????????????&???~???iO???z??v?^?m???? ????????I?