On Thu, 2012-10-11 at 19:12 +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. > > v1->v2 > - add a rollback for reinstalling a notify handler. > > Signed-off-by: Yasuaki Ishimatsu <isimatu.yasuaki@xxxxxxxxxxxxxx> Thanks for the update. Looks good. Reviewed-by: Toshi Kani <toshi.kani@xxxxxx> -Toshi > > --- > drivers/acpi/scan.c | 21 ++++++++++++++++++--- > drivers/base/dd.c | 22 +++++++++++++++++----- > include/linux/device.h | 2 +- > 3 files changed, 36 insertions(+), 9 deletions(-) > > Index: linux-3.6/drivers/acpi/scan.c > =================================================================== > --- linux-3.6.orig/drivers/acpi/scan.c 2012-10-11 18:31:40.189019503 +0900 > +++ linux-3.6/drivers/acpi/scan.c 2012-10-11 18:42:35.669041641 +0900 > @@ -445,18 +445,29 @@ 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) > + goto rollback; > + } > } > acpi_dev->driver = NULL; > acpi_dev->driver_data = NULL; > > put_device(dev); > return 0; > + > +rollback: > + if (acpi_drv->ops.notify) > + acpi_device_install_notify_handler(acpi_dev); > + > + return ret; > } > > struct bus_type acpi_bus_type = { > @@ -1226,11 +1237,15 @@ 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 2012-10-11 18:31:40.191019505 +0900 > +++ linux-3.6/drivers/base/dd.c 2012-10-11 18:31:46.873020548 +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 2012-10-11 18:31:40.194019508 +0900 > +++ linux-3.6/include/linux/device.h 2012-10-11 18:31:46.881020556 +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-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
