Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755121AbZFEQAB (ORCPT ); Fri, 5 Jun 2009 12:00:01 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751949AbZFEP7x (ORCPT ); Fri, 5 Jun 2009 11:59:53 -0400 Received: from g4t0014.houston.hp.com ([15.201.24.17]:8676 "EHLO g4t0014.houston.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751673AbZFEP7w (ORCPT ); Fri, 5 Jun 2009 11:59:52 -0400 Date: Fri, 5 Jun 2009 09:59:54 -0600 From: Alex Chiang To: Bjorn Helgaas Cc: Kenji Kaneshige , lenb@kernel.org, linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org Subject: Re: [PATCH v2 07/11] ACPI: acpi_pci_unbind should clean up properly after acpi_pci_bind Message-ID: <20090605155954.GA11891@ldl.fc.hp.com> References: <20090604054504.18802.21690.stgit@bob.kio> <4A2788FA.2050606@jp.fujitsu.com> <20090604233521.GA12900@ethanol> <200906050949.02097.bjorn.helgaas@hp.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200906050949.02097.bjorn.helgaas@hp.com> User-Agent: Mutt/1.5.17+20080114 (2008-01-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2762 Lines: 81 * Bjorn Helgaas : > On Thursday 04 June 2009 05:35:21 pm Alex Chiang wrote: > > * Kenji Kaneshige : > > > > > > I have a concern about this change. > > > > > > The acpi_pci_irq_del_prt() against dev->bus removes not only > > > the _PRT entries for PCI function corresponding to specified > > > acpi_device, but also other _PRT entries for working PCI > > > devices/functions on the same bus. As a result, interrupt > > > initialization for those PCI functions would no longer work > > > properly after that. > > > > > > So I think we should not call acpi_pci_irq_del_prt() against > > > dev->bus. > > > > Thanks for the review. I agree with you. > > I agree that this respun version makes things more the way they were, > so in that sense, it should do no harm. But I still have the niggling > concern that .bind() adds _PRT info for non-bridges, and there's no > corresponding removal. There should be some path that makes this > more symmetric. The comment in acpi_pci_bind doesn't seem to know if you can even have a _PRT for non-bridges. The spec (3.0b) says that _PRT is required for all root bridges, but doesn't mention anything about non-bridge devices. My gut feeling is the way to cure the symmetry is to remove the path in .bind() that adds _PRT for non-bridges, but I'm a little hesitant to do that without knowing for sure. I think for this patch, the Hippocratic approach is the right one for now. Thanks. /ac > > Here is a respun version of this patch. > > > > From: Alex Chiang > > > > ACPI: acpi_pci_unbind should clean up properly after acpi_pci_bind > > > > In acpi_pci_bind, we set device->ops.bind and device->ops.unbind, but > > never clear them out. > > > > Cc: Bjorn Helgaas > > Signed-off-by: Alex Chiang > > --- > > diff --git a/drivers/acpi/pci_bind.c b/drivers/acpi/pci_bind.c > > index 62cb383..c9cc650 100644 > > --- a/drivers/acpi/pci_bind.c > > +++ b/drivers/acpi/pci_bind.c > > @@ -109,11 +109,13 @@ static int acpi_pci_unbind(struct acpi_device *device) > > struct pci_dev *dev; > > > > dev = acpi_get_pci_dev(device->handle); > > - if (!dev) > > + if (!dev || !dev->subordinate) > > return 0; > > > > - if (dev->subordinate) > > - acpi_pci_irq_del_prt(dev->subordinate); > > + acpi_pci_irq_del_prt(dev->subordinate); > > + > > + device->ops.bind = NULL; > > + device->ops.unbind = NULL; > > > > pci_dev_put(dev); > > return 0; > > > > -- 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/