Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763395AbYBEXqq (ORCPT ); Tue, 5 Feb 2008 18:46:46 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1761019AbYBEXqZ (ORCPT ); Tue, 5 Feb 2008 18:46:25 -0500 Received: from cantor.suse.de ([195.135.220.2]:40052 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760746AbYBEXqX (ORCPT ); Tue, 5 Feb 2008 18:46:23 -0500 Date: Tue, 5 Feb 2008 15:44:13 -0800 From: Greg KH To: Jean Delvare Cc: markus.rechberger@amd.com, "Matt_Domsch@dell.com" , Jos?? Luis Tall??n , "Douglas_Warzecha@dell.com" , "Abhay_Salunke@dell.com" , linux-kernel@vger.kernel.org, Michael E Brown , Kay Sievers Subject: Re: 2.6.24 breaks BIOS updates on all Dell machines Message-ID: <20080205234413.GA9386@suse.de> References: <20080129184129.GA23681@kroah.com> <20080205064547.GA20384@suse.de> <20080205211642.2c49e3d0@hyperion.delvare> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20080205211642.2c49e3d0@hyperion.delvare> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3379 Lines: 77 On Tue, Feb 05, 2008 at 09:16:42PM +0100, Jean Delvare wrote: > On Mon, 4 Feb 2008 22:45:47 -0800, Greg KH wrote: > > On Tue, Jan 29, 2008 at 11:15:22PM +0100, Jean Delvare wrote: > > > I'm a bit confused. It seems to me that the "class devices" are named > > > differently in recent kernels. The i2c-dev class devices were originally > > > showing as i2c-%d in their parent device directories (causing the > > > collision), and now show as i2c-dev:i2c-%d. This suggests that the > > > collision the patch above was trying to solve is in fact already fixed > > > (by prefixing the device name with the class name). The good news is > > > that it would mean that we can just revert the patch in question... > > > > > > But quite frankly I'm not really sure, the class devices look different > > > on every kernel I looked at, depending on the version and whether > > > CONFIG_SYSFS_DEPRECATED is set or not. > > > > THe naming is different depending on that sysfs variable, yes. But it > > should be consistant other than that. If not, please let me know. > > > > And yes, we did have to add the ":" a while ago to handle the namespace > > collisions we were having. > > OK, I am officially confused now. Heh, it is a mess :) > This is 2.6.24, CONFIG_SYSFS_DEPRECATED=y: > > # ls -l /sys/class/i2c-adapter/i2c-0 > total 0 > lrwxrwxrwx 1 root root 0 f?v 5 18:07 device -> ../../../devices/pci0000:00/0000:00:01.0/0000:01:00.0 > lrwxrwxrwx 1 root root 0 f?v 5 18:17 i2c-dev:i2c-0 -> ../../../class/i2c-dev/i2c-0 > -r--r--r-- 1 root root 4096 f?v 5 18:07 name > drwxr-xr-x 2 root root 0 f?v 5 18:17 power > lrwxrwxrwx 1 root root 0 f?v 5 18:07 subsystem -> ../../../class/i2c-adapter > -rw-r--r-- 1 root root 4096 f?v 5 2008 uevent > > 2.6.24 rebuilt without CONFIG_SYSFS_DEPRECATED: > > # ls -l /sys/class/i2c-adapter/i2c-0/ > total 0 > lrwxrwxrwx 1 root root 0 f?v 5 18:42 device -> ../../../../../../devices/pci0000:00/0000:00:01.0/0000:01:00.0 > drwxr-xr-x 3 root root 0 f?v 5 18:42 i2c-0 > -r--r--r-- 1 root root 4096 f?v 5 18:31 name > drwxr-xr-x 2 root root 0 f?v 5 18:42 power > lrwxrwxrwx 1 root root 0 f?v 5 18:31 subsystem -> ../../../../../../class/i2c-adapter > -rw-r--r-- 1 root root 4096 f?v 5 2008 uevent > > The latter corresponds to what older kernels had ("i2c-0"). This means > that enabling CONFIG_SYSFS_DEPRECATED causes the i2c-dev class device > names to change. Yes. Well, no, not really. The class device names are the same, it's just that it is a symlink in the DEPRECATED=Y name and a real directory in the =N case. > Isn't it supposed to be exactly the other way around, i.e. enabling > CONFIG_SYSFS_DEPRECATED should preserve the names as they were in > older kernels? The real name is the same (look above, it's really called "i2c-0" in both cases, just that the symlink in the =Y case has to have a different name to handle the fact that there could be duplicate names in this format. Does that help? It's really to keep older programs still work properly. The =N case is what you should pay attention to for all modern distros. thanks, greg k-h -- 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/