From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243Ab3KAOIl (ORCPT ); Fri, 1 Nov 2013 10:08:41 -0400 Received: from g4t0015.houston.hp.com ([15.201.24.18]:43907 "EHLO g4t0015.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751552Ab3KAOIk (ORCPT ); Fri, 1 Nov 2013 10:08:40 -0400 Date: Fri, 1 Nov 2013 09:08:37 -0500 From: scameron@beardog.cce.hp.com To: Andrew Morton Cc: Tomas Henzl , Jens Axboe , stephenmcameron@gmail.com, mikem@beardog.cce.hp.com, linux-kernel@vger.kernel.org, scameron@beardog.cce.hp.com Subject: Re: [PATCH] cciss: return 0 from driver probe function on success, not 1 Message-ID: <20131101140837.GO31390@beardog.cce.hp.com> References: <20131029184135.5505.77412.stgit@beardog.cce.hp.com> <52700541.70405@kernel.dk> <20131031144241.25090ab7a6c0b668c5c1c2b2@linux-foundation.org> <20131031215444.GN31390@beardog.cce.hp.com> <20131031150618.fa9430269e0de7a5ebad1387@linux-foundation.org> <5273A765.6080705@redhat.com> <20131101063110.6a390f48.akpm@linux-foundation.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131101063110.6a390f48.akpm@linux-foundation.org> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Nov 01, 2013 at 06:31:10AM -0700, Andrew Morton wrote: > On Fri, 01 Nov 2013 14:06:45 +0100 Tomas Henzl wrote: > > > The problem in kernel is that the error handling in local_pci_probe > > and in __pci_device_probe is different for ret values > 0, > > so we should fix it somewhere so it is in sync. > > The documentation states that the probe function should return zero on success > > so what about this - > > > > This would bring the handling to sync > > diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c > > index 98f7b9b..200a071 100644 > > --- a/drivers/pci/pci-driver.c > > +++ b/drivers/pci/pci-driver.c > > @@ -317,8 +317,6 @@ __pci_device_probe(struct pci_driver *drv, struct pci_dev *pci_dev) > > id = pci_match_device(drv, pci_dev); > > if (id) > > error = pci_call_probe(drv, pci_dev, id); > > - if (error >= 0) > > - error = 0; > > } > > return error; > > } > > ah, there it is. > > This change would turn semi-kaput drivers into kaput-kaput drivers. It > would be better to add a runtime warning here so those drivers get > fixed. Such a warning would need to reliably identify the offending > probe function so a simple WARN_ON() wouldn't be sufficient. > FWIW, I just booted up with the following change: diff --git a/drivers/pci/pci-driver.c b/drivers/pci/pci-driver.c index 98f7b9b..ef71bb5 100644 --- a/drivers/pci/pci-driver.c +++ b/drivers/pci/pci-driver.c @@ -264,9 +264,16 @@ static long local_pci_probe(void *_ddi) pm_runtime_get_sync(dev); pci_dev->driver = pci_drv; rc = pci_drv->probe(pci_dev, ddi->id); - if (rc) { + if (rc < 0) { pci_dev->driver = NULL; pm_runtime_put_sync(dev); + } else { + if (rc > 0) { + dev_warn(dev, + "Driver probe function returned %d, greater than 0\n", rc); + rc = 0; + + } } return rc; } And, [scameron@localhost linux-3.12-rc6]$ dmesg | grep 'Driver probe' [scameron@localhost linux-3.12-rc6]$ Not that it means all that much since I don't have hardware for the majority of drivers, obviously. I think the above should make drivers with probe functions returning > 0 "work" again, but with a warning. The question would be, are there drivers which return > 0 and by this value intend to convey that the probe function has failed? -- steve