From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756118Ab3G2WiI (ORCPT ); Mon, 29 Jul 2013 18:38:08 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:60477 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754891Ab3G2WiG (ORCPT ); Mon, 29 Jul 2013 18:38:06 -0400 Date: Mon, 29 Jul 2013 15:38:05 -0700 From: Greg KH To: "Winkler, Tomas" Cc: "arnd@arndb.de" , "linux-kernel@vger.kernel.org" , "Ovsyanikov, Natalia" Subject: Re: [char-misc-next 2/3] mei: adding sysfs fw_status attribute Message-ID: <20130729223805.GA9677@kroah.com> References: <1374680517-30894-1-git-send-email-tomas.winkler@intel.com> <1374680517-30894-3-git-send-email-tomas.winkler@intel.com> <20130724160008.GA17083@kroah.com> <5B8DA87D05A7694D9FA63FD143655C1B1AE738C0@HASMSX106.ger.corp.intel.com> <20130724162605.GA9700@kroah.com> <5B8DA87D05A7694D9FA63FD143655C1B1AE73993@HASMSX106.ger.corp.intel.com> <20130724202957.GA14913@kroah.com> <5B8DA87D05A7694D9FA63FD143655C1B1AE76B1B@HASMSX106.ger.corp.intel.com> <20130728153155.GA6781@kroah.com> <5B8DA87D05A7694D9FA63FD143655C1B1AE77A4E@HASMSX106.ger.corp.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5B8DA87D05A7694D9FA63FD143655C1B1AE77A4E@HASMSX106.ger.corp.intel.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Jul 29, 2013 at 10:27:06PM +0000, Winkler, Tomas wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > > Just to make sure, is this what you're suggesting ? > > > > > > > > > > > > > > device->groups = mei_attr_groups > > > > > > > mei_misc_device.parent = device; ret = > > > > > > > misc_register(&mei_misc_device); > > > > > > > > > > > > Yes, that should work. If not, please let me know, the code > > > > > > underwent some changes in 3.11-rc2. > > > > > > > > > > I don' t see the file being created. > > > > > Not sure if the misc_register setup the parent sysfs as well. > > > > > > > > Oops, wait, the parent is already registered, that's not going to > > > > work, you want to create the files for the device itself that you > > > > are creating, so set the - > > > > >groups field for that device. > > > > > > > > sorry about that. > > > > > > So is this okay to go as is? > > > > What is "this"? > > The intentions was to create the sysfs on a parent pci device, and > these are already created . You can't create attributes on a device you do not "own", that will be racy and prone to cause big problems (your callback will not with the "right" device usually, as your parent might not "be" a pci device in the future...) > The only reason I wanted do it here as this is true for any parent pci > device we support currently that registers with mei. > > Either this code ode is still confusing because I'm doing something > wrong here or your mind Is set on fixing this particular user space > race issue. Probably both... Either way, you can't create sysfs files in a racy way, I'm going through the whole kernel tree to clean them all up, I'm not going to add new race conditions today that I need to fix up tomorrow, my patch count is high enough as it is :) thanks, greg k-h