From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752534AbYLSQyS (ORCPT ); Fri, 19 Dec 2008 11:54:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751556AbYLSQyE (ORCPT ); Fri, 19 Dec 2008 11:54:04 -0500 Received: from kroah.org ([198.145.64.141]:37067 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751310AbYLSQyD (ORCPT ); Fri, 19 Dec 2008 11:54:03 -0500 Date: Fri, 19 Dec 2008 08:52:56 -0800 From: Greg KH To: Ben Dooks Cc: linux-kernel@vger.kernel.org, Andrew Morton Subject: Re: device driver probe return codes Message-ID: <20081219165256.GD14583@kroah.com> References: <20081216215331.GH12431@fluff.org.uk> <20081216234128.05a343bb.akpm@linux-foundation.org> <20081219051436.GA29543@kroah.com> <20081219081636.GK12431@fluff.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20081219081636.GK12431@fluff.org.uk> 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 On Fri, Dec 19, 2008 at 08:16:36AM +0000, Ben Dooks wrote: > On Thu, Dec 18, 2008 at 09:14:36PM -0800, Greg KH wrote: > > On Tue, Dec 16, 2008 at 11:41:28PM -0800, Andrew Morton wrote: > > > On Tue, 16 Dec 2008 21:53:31 +0000 Ben Dooks wrote: > > > > > > > I would like some feedback on the following regarding some > > > > form of standardising return codes from a device driver probe > > > > to try and stop some basic mistakes. > > > > > > > > This document is not complete, any additions would be welcone. > > > > Hm, shouldn't you have at least copied me on this? > > Sorry, assumed you'd be reading linux-kernel. I try to, but things get through at at times. Please always cc: me if you want me to read it. > > What is this for? Each of the different busses treat return codes for > > their probe functions a bit differently, are you wanting to unify them? > > And if so, why? > > I was trying to make a guide for people to try and avoid the general > mistakes such as returning -ENODEV when it clearly isn't the right > thing to do. There are a number of drivers which return this causing > confusion as to why devices are not being bound as they neither print > an error nor cause the driver core to print anything [1]. > > The idea is to provide a guide to what error numbers are acceptable > to return and what the best return code for the common situations > that drivers tend to do and what to avoid. > > As a note, having looked at the base driver, pci, platform and i2c > they all pass the error straight back to the core driver probe. Fair enough, care to respin this and send it out to me for review? thanks, greg k-h