From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757803Ab3ANXXd (ORCPT ); Mon, 14 Jan 2013 18:23:33 -0500 Received: from g1t0026.austin.hp.com ([15.216.28.33]:26202 "EHLO g1t0026.austin.hp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757043Ab3ANXXc (ORCPT ); Mon, 14 Jan 2013 18:23:32 -0500 Message-ID: <1358205223.14145.108.camel@misato.fc.hp.com> Subject: Re: [PATCH 5/5] ACPI / scan: Add second pass to acpi_bus_trim() From: Toshi Kani To: "Rafael J. Wysocki" Cc: ACPI Devel Maling List , Bjorn Helgaas , LKML , Yinghai Lu , Jiang Liu , Taku Izumi Date: Mon, 14 Jan 2013 16:13:43 -0700 In-Reply-To: <9393976.KUs5xrSxYx@vostro.rjw.lan> References: <3885603.ydrrB7OEKf@vostro.rjw.lan> <9393976.KUs5xrSxYx@vostro.rjw.lan> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.4.4 (3.4.4-2.fc17) Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2013-01-14 at 22:39 +0100, Rafael J. Wysocki wrote: > From: Rafael J. Wysocki > > Make acpi_bus_trim() work in analogy with acpi_bus_scan() and carry > out two passes such that ACPI drivers will be detached from device > nodes being removed in the first pass and the device nodes themselves > will be removed in the second pass. > > For this purpose split the driver unregistration out of > acpi_bus_remove() into a new routine, acpi_bus_device_detach(), that > will be executed by acpi_bus_trim() in the additional first pass as > a post-order callback. > > This is necessary, because some ACPI drivers' .remove() routines > unregister struct device objects associated with the ACPI device > nodes being removed and that needs to happen while the ACPI > device nodes are still around (for example, in case they need to be > used for power management or similar things at that time). > > Signed-off-by: Rafael J. Wysocki I'd suggest to add some comment stating that acpi_bus_device_detach() acpi_bus_remove() are post-order callbacks. I do not think many people recognize it by just looking the calls to acpi_walk_namespace(). Otherwise, the patchset looks good. For the patch series: Acked-by: Toshi Kani Thanks, -Toshi > --- > drivers/acpi/scan.c | 44 ++++++++++++++++++++++++++++---------------- > 1 file changed, 28 insertions(+), 16 deletions(-) > > Index: linux-pm/drivers/acpi/scan.c > =================================================================== > --- linux-pm.orig/drivers/acpi/scan.c > +++ linux-pm/drivers/acpi/scan.c > @@ -1425,22 +1425,6 @@ static void acpi_device_set_id(struct ac > } > } > > -static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used, > - void *not_used, void **ret_not_used) > -{ > - struct acpi_device *dev = NULL; > - > - if (acpi_bus_get_device(handle, &dev)) > - return AE_OK; > - > - dev->removal_type = ACPI_BUS_REMOVAL_EJECT; > - device_release_driver(&dev->dev); > - > - acpi_device_unregister(dev); > - > - return AE_OK; > -} > - > void acpi_init_device_object(struct acpi_device *device, acpi_handle handle, > int type, unsigned long long sta) > { > @@ -1647,8 +1631,36 @@ int acpi_bus_add(acpi_handle handle) > } > EXPORT_SYMBOL(acpi_bus_add); > > +static acpi_status acpi_bus_device_detach(acpi_handle handle, u32 lvl_not_used, > + void *not_used, void **ret_not_used) > +{ > + struct acpi_device *device = NULL; > + > + if (!acpi_bus_get_device(handle, &device)) { > + device->removal_type = ACPI_BUS_REMOVAL_EJECT; > + device_release_driver(&device->dev); > + } > + return AE_OK; > +} > + > +static acpi_status acpi_bus_remove(acpi_handle handle, u32 lvl_not_used, > + void *not_used, void **ret_not_used) > +{ > + struct acpi_device *device = NULL; > + > + if (!acpi_bus_get_device(handle, &device)) > + acpi_device_unregister(device); > + > + return AE_OK; > +} > + > int acpi_bus_trim(struct acpi_device *start) > { > + /* Detach all ACPI drivers from the device nodes being removed. */ > + acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL, > + acpi_bus_device_detach, NULL, NULL); > + acpi_bus_device_detach(start->handle, 0, NULL, NULL); > + /* Remove the device nodes. */ > acpi_walk_namespace(ACPI_TYPE_ANY, start->handle, ACPI_UINT32_MAX, NULL, > acpi_bus_remove, NULL, NULL); > acpi_bus_remove(start->handle, 0, NULL, NULL); >