From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934103Ab2DLND3 (ORCPT ); Thu, 12 Apr 2012 09:03:29 -0400 Received: from mail.mev.co.uk ([62.49.15.74]:41507 "EHLO mail.mev.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756590Ab2DLND2 (ORCPT ); Thu, 12 Apr 2012 09:03:28 -0400 Message-ID: <4F86D294.3050108@mev.co.uk> Date: Thu, 12 Apr 2012 14:03:16 +0100 From: Ian Abbott User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:11.0) Gecko/20120330 Thunderbird/11.0.1 MIME-Version: 1.0 To: Greg KH CC: Ian Abbott , "devel@driverdev.osuosl.org" , Gerard Snitselaar , "linux-kernel@vger.kernel.org" , "fmhess@users.sourceforge.net" Subject: Re: [PATCH v2] staging: comedi: resolve section mismatch in s626 References: <1332123921-14347-1-git-send-email-dev@snitselaar.org> <20120319030925.GB22956@perelman.Home> <20120319163103.GC3694@kroah.com> <20120319164325.GA31833@perelman.Home> <20120319224649.GA7679@perelman.Home> <20120319232656.GB6386@kroah.com> <4F798416.8040709@mev.co.uk> <20120410182438.GB2052@kroah.com> In-Reply-To: <20120410182438.GB2052@kroah.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2012/04/10 07:24 PM, Greg KH wrote: > On Mon, Apr 02, 2012 at 11:48:54AM +0100, Ian Abbott wrote: >> On 2012-03-19 23:26, Greg KH wrote: >>> On Mon, Mar 19, 2012 at 03:46:49PM -0700, Gerard Snitselaar wrote: >>>> I looked at this a bit more. It looks like they lose visibility to the >>>> pci_dev structure. >>>> >>>> *_probe() >>>> comedi_pci_auto_config() pci_dev >>>> comedi_auto_config() pci_dev->dev >>>> comedi_device_attach() ?? >>>> driv->attach() ??<= iterate through pci devices. >>>> >>>> Most of the examples I have looked at so far use for_each_pci_dev() to >>>> find the device, and s626 shortcuts it a bit by directly making calls >>>> to pci_get_subsys() with specific ids. They all verify they have the >>>> right device by checking the bus and slot that are grabbed from the >>>> pci_dev in comedi_pci_auto_config() and passed down. >>> >>> Ugh, surely there's a way to keep the pci dev through the >>> comedi_device_attach() call, right? >> >> comedi_device_attach() is also called for the COMEDI_DEVCONFIG ioctl >> for "manually" configuring a comedi device, and that has no idea >> about struct pci_dev, etc. >> >> I recently posted a series of patches that allows lower-level comedi >> drivers to supply separate hooks for auto-configuring PCI devices or >> USB devices without abusing the old "manual configuration" code >> paths, see . >> >> The old loop that searches the PCI bus is still needed for the >> "manual configuration" code path. > > So, now that I've applied your patches, this patch isn't needed anymore, > right? Or should it be reworked to use the new interfaces? I think it's still needed as that the comedi_driver->attach() hook is still needed to support manual configuration by the COMEDI_DEVCONFIG ioctl, and the existing code really shouldn't be looking in s626_pci_table[] as it's tagged __devinitconst. I never saw any mismatched section warnings when I compiled a linux-next kernel on my system with a full set of comedi drivers, even with CONFIG_DEBUG_SECTION_MISMATCH configured. I'm not sure why not, unless it has something to do with me building the kernel with a separate build directory. The new comedi_driver->attach_pci() hook should be implemented for this driver as well, and it's on my "todo" list (in my head!). -- -=( Ian Abbott @ MEV Ltd. E-mail: )=- -=( Tel: +44 (0)161 477 1898 FAX: +44 (0)161 718 3587 )=-