Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757193AbZDRVKU (ORCPT ); Sat, 18 Apr 2009 17:10:20 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754568AbZDRVKF (ORCPT ); Sat, 18 Apr 2009 17:10:05 -0400 Received: from hera.kernel.org ([140.211.167.34]:60836 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751672AbZDRVKE (ORCPT ); Sat, 18 Apr 2009 17:10:04 -0400 Message-ID: <49EA4118.2040701@kernel.org> Date: Sat, 18 Apr 2009 14:07:36 -0700 From: Yinghai Lu User-Agent: Thunderbird 2.0.0.19 (X11/20081227) MIME-Version: 1.0 To: Kay Sievers CC: Greg KH , Linus Torvalds , Jesse Barnes , Andrew Morton , "H. Peter Anvin" , Ingo Molnar , Thomas Gleixner , "linux-kernel@vger.kernel.org" , linux-pci@vger.kernel.org Subject: Re: [PATCH] pci: keep pci device resource name pointer right. References: <20090416172803.GB16618@elte.hu> <20090416235452.GE21405@elte.hu> <20090417131633.GA30578@elte.hu> <49E8FD0B.2050308@zytor.com> <49E96731.1000501@kernel.org> <49EA27B9.3030004@kernel.org> <20090418192314.GA22107@suse.de> <1240086446.2411.9.camel@poy> In-Reply-To: <1240086446.2411.9.camel@poy> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2965 Lines: 82 Kay Sievers wrote: > On Sat, 2009-04-18 at 22:00 +0200, Kay Sievers wrote: >> On Sat, Apr 18, 2009 at 21:23, Greg KH wrote: >>> On Sat, Apr 18, 2009 at 12:19:21PM -0700, Yinghai Lu wrote: >>>> Linus Torvalds wrote: >>>>> Can we not make the rule be that the name should just be set before? >> I guess, that's what they do already, otherwise they could not use dev_name(). >> >>>> pci_bus_add_device will call device_add. >>>> >>>> actually in device_add >>>> >>>> /* first, register with generic layer. */ >>>> error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); >>>> if (error) >>>> goto Error; >>>> >>>> will get one new name for that kobj, old name is freed. >>>> >>>> Will try to make kobject_add more smart to reuse the old one. >>> I don't understand the problem here, how are you going to change the >>> kobject core? Is this just because you aren't getting a name for the >>> resource? If so, why would the driver core care about this? >> Seems a bit odd what we do when registering a device. >> >> Usually one sets the name with dev_set_name() which will name the >> kobject. When one later registers the device, we reallocate the same >> name, so the pointer changes. I guess the problem here is that the pci >> code remembers the name pointer after it was set, but it will not be >> the same after the device is live. >> >> We should probably make device_add() pass a NULL as the name, and >> kobject_add() in that case use the name that is properly set already. > > Only to see if we are on the right track, does that fix the problem? If > yes, we will fix it properly without the NULL hack deep in the kobject > call. > > Thanks, > Kay > > diff --git a/drivers/base/core.c b/drivers/base/core.c > index d230ff4..1969b20 100644 > --- a/drivers/base/core.c > +++ b/drivers/base/core.c > @@ -890,8 +890,8 @@ int device_add(struct device *dev) > if (parent) > set_dev_node(dev, dev_to_node(parent)); > > - /* first, register with generic layer. */ > - error = kobject_add(&dev->kobj, dev->kobj.parent, "%s", dev_name(dev)); > + /* we require the name to be set before, and pass NULL */ > + error = kobject_add(&dev->kobj, dev->kobj.parent, NULL); > if (error) > goto Error; > > diff --git a/lib/kobject.c b/lib/kobject.c > index a6dec32..48565d6 100644 > --- a/lib/kobject.c > +++ b/lib/kobject.c > @@ -218,6 +218,9 @@ int kobject_set_name_vargs(struct kobject *kobj, const char *fmt, > const char *old_name = kobj->name; > char *s; > > + if (kobj->name && !fmt) > + return 0; > + > kobj->name = kvasprintf(GFP_KERNEL, fmt, vargs); > if (!kobj->name) > return -ENOMEM; > it works well. Thanks YH -- 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/