Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757250Ab2JJBIS (ORCPT ); Tue, 9 Oct 2012 21:08:18 -0400 Received: from fgwmail6.fujitsu.co.jp ([192.51.44.36]:43826 "EHLO fgwmail6.fujitsu.co.jp" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757216Ab2JJBIP (ORCPT ); Tue, 9 Oct 2012 21:08:15 -0400 X-SecurityPolicyCheck: OK by SHieldMailChecker v1.7.4 Message-ID: <5074CA61.3010802@jp.fujitsu.com> Date: Wed, 10 Oct 2012 10:07:45 +0900 From: Yasuaki Ishimatsu User-Agent: Mozilla/5.0 (Windows NT 5.1; rv:15.0) Gecko/20120907 Thunderbird/15.0.1 MIME-Version: 1.0 To: Toshi Kani CC: , , , , Subject: Re: acpi : acpi_bus_trim() stops removing devices when failing to remove the device References: <5073E4CC.3090600@jp.fujitsu.com> <1349800566.23493.9.camel@misato.fc.hp.com> In-Reply-To: <1349800566.23493.9.camel@misato.fc.hp.com> Content-Type: text/plain; charset="UTF-8"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6225 Lines: 178 Hi Toshi, 2012/10/10 1:36, Toshi Kani wrote: > On Tue, 2012-10-09 at 17:48 +0900, Yasuaki Ishimatsu wrote: >> acpi_bus_trim() stops removing devices, when acpi_bus_remove() return error >> number. But acpi_bus_remove() cannot return error number correctly. >> acpi_bus_remove() only return -EINVAL, when dev argument is NULL. Thus even if >> device cannot be removed correctly, acpi_bus_trim() ignores and continues to >> remove devices. acpi_bus_hot_remove_device() uses acpi_bus_trim() for removing >> devices. Therefore acpi_bus_hot_remove_device() can send "_EJ0" to firmware, >> even if the device is running on the system. In this case, the system cannot >> work well. >> >> Vasilis hit the bug at memory hotplug and reported it as follow: >> https://lkml.org/lkml/2012/9/26/318 >> >> So acpi_bus_trim() should check whether device was removed or not correctly. >> The patch adds error check into some functions to remove the device. >> >> Applying the patch, acpi_bus_trim() stops removing devices when failing >> to remove the device. But I think there is no impact with the >> exceptionof CPU and Memory hotplug path. Because other device also fails >> but the fail is an irregular case like device is NULL. >> >> Signed-off-by: Yasuaki Ishimatsu >> >> --- >> drivers/acpi/scan.c | 15 ++++++++++++--- >> drivers/base/dd.c | 22 +++++++++++++++++----- >> include/linux/device.h | 2 +- >> 3 files changed, 30 insertions(+), 9 deletions(-) >> >> Index: linux-3.6/drivers/acpi/scan.c >> =================================================================== >> --- linux-3.6.orig/drivers/acpi/scan.c 2012-10-09 17:25:40.956496325 +0900 >> +++ linux-3.6/drivers/acpi/scan.c 2012-10-09 17:25:55.405497800 +0900 >> @@ -445,12 +445,17 @@ static int acpi_device_remove(struct dev >> { >> struct acpi_device *acpi_dev = to_acpi_device(dev); >> struct acpi_driver *acpi_drv = acpi_dev->driver; >> + int ret; >> >> if (acpi_drv) { >> if (acpi_drv->ops.notify) >> acpi_device_remove_notify_handler(acpi_dev); >> - if (acpi_drv->ops.remove) >> - acpi_drv->ops.remove(acpi_dev, acpi_dev->removal_type); >> + if (acpi_drv->ops.remove) { >> + ret = acpi_drv->ops.remove(acpi_dev, >> + acpi_dev->removal_type); >> + if (ret) > > Hi Yasuaki, > > Shouldn't the notify handler be reinstalled here if it was removed by > the acpi_device_remove_notify_handler() above? I do not reinstall the notify handler. The function has not been removed on linux-3.6. And the patch is created on linux-3.6. So the function remains in the patch. Thanks, Yasuaki Ishimatsu > > Thanks, > -Toshi > >> + return ret; >> + } >> } >> acpi_dev->driver = NULL; >> acpi_dev->driver_data = NULL; >> @@ -1226,11 +1231,15 @@ static int acpi_device_set_context(struc >> >> static int acpi_bus_remove(struct acpi_device *dev, int rmdevice) >> { >> + int ret; >> + >> if (!dev) >> return -EINVAL; >> >> dev->removal_type = ACPI_BUS_REMOVAL_EJECT; >> - device_release_driver(&dev->dev); >> + ret = device_release_driver(&dev->dev); >> + if (ret) >> + return ret; >> >> if (!rmdevice) >> return 0; >> Index: linux-3.6/drivers/base/dd.c >> =================================================================== >> --- linux-3.6.orig/drivers/base/dd.c 2012-10-01 08:47:46.000000000 +0900 >> +++ linux-3.6/drivers/base/dd.c 2012-10-09 17:25:55.442497825 +0900 >> @@ -475,9 +475,10 @@ EXPORT_SYMBOL_GPL(driver_attach); >> * __device_release_driver() must be called with @dev lock held. >> * When called for a USB interface, @dev->parent lock must be held as well. >> */ >> -static void __device_release_driver(struct device *dev) >> +static int __device_release_driver(struct device *dev) >> { >> struct device_driver *drv; >> + int ret = 0; >> >> drv = dev->driver; >> if (drv) { >> @@ -493,9 +494,11 @@ static void __device_release_driver(stru >> pm_runtime_put_sync(dev); >> >> if (dev->bus && dev->bus->remove) >> - dev->bus->remove(dev); >> + ret = dev->bus->remove(dev); >> else if (drv->remove) >> - drv->remove(dev); >> + ret = drv->remove(dev); >> + if (ret) >> + goto rollback; >> devres_release_all(dev); >> dev->driver = NULL; >> dev_set_drvdata(dev, NULL); >> @@ -506,6 +509,12 @@ static void __device_release_driver(stru >> dev); >> >> } >> + >> + return ret; >> + >> +rollback: >> + driver_sysfs_add(dev); >> + return ret; >> } >> >> /** >> @@ -515,16 +524,19 @@ static void __device_release_driver(stru >> * Manually detach device from driver. >> * When called for a USB interface, @dev->parent lock must be held. >> */ >> -void device_release_driver(struct device *dev) >> +int device_release_driver(struct device *dev) >> { >> + int ret; >> /* >> * If anyone calls device_release_driver() recursively from >> * within their ->remove callback for the same device, they >> * will deadlock right here. >> */ >> device_lock(dev); >> - __device_release_driver(dev); >> + ret = __device_release_driver(dev); >> device_unlock(dev); >> + >> + return ret; >> } >> EXPORT_SYMBOL_GPL(device_release_driver); >> >> Index: linux-3.6/include/linux/device.h >> =================================================================== >> --- linux-3.6.orig/include/linux/device.h 2012-10-01 08:47:46.000000000 +0900 >> +++ linux-3.6/include/linux/device.h 2012-10-09 17:25:55.479497852 +0900 >> @@ -834,7 +834,7 @@ static inline void *dev_get_platdata(con >> * for information on use. >> */ >> extern int __must_check device_bind_driver(struct device *dev); >> -extern void device_release_driver(struct device *dev); >> +extern int device_release_driver(struct device *dev); >> extern int __must_check device_attach(struct device *dev); >> extern int __must_check driver_attach(struct device_driver *drv); >> extern int __must_check device_reprobe(struct device *dev); >> > > -- 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/