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. 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.

device_release_driver() can return error value by the patch. But the change
does not impact other caller function excluding acpi_bus_trim(), since all
of them does not check return value of device_releae_driver().

Signed-off-by: Yasuaki Ishimatsu <isimatu.yasu...@jp.fujitsu.com>

---
 drivers/acpi/scan.c    |   15 ++++++++++++---
 drivers/base/dd.c      |   22 +++++++++++++++++-----
 include/linux/device.h |    2 +-
 3 files changed, 30 insertions(+), 9 deletions(-)

Index: linux-3.5-rc6/drivers/acpi/scan.c
===================================================================
--- linux-3.5-rc6.orig/drivers/acpi/scan.c      2012-07-13 15:10:46.136790418 
+0900
+++ linux-3.5-rc6/drivers/acpi/scan.c   2012-07-13 15:12:41.364349387 +0900
@@ -425,12 +425,17 @@ 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)
+                               return ret;
+               }
        }
        acpi_dev->driver = NULL;
        acpi_dev->driver_data = NULL;
@@ -1208,11 +1213,15 @@ 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-3.5-rc6/drivers/base/dd.c
===================================================================
--- linux-3.5-rc6.orig/drivers/base/dd.c        2012-07-13 15:10:46.136790418 
+0900
+++ linux-3.5-rc6/drivers/base/dd.c     2012-07-13 15:14:13.895193383 +0900
@@ -464,9 +464,10 @@ 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) {
@@ -482,9 +483,11 @@ 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;
                klist_remove(&dev->p->knode_driver);
@@ -494,6 +497,12 @@ static void __device_release_driver(stru
                                                     dev);

        }
+
+       return ret;
+
+rollback:
+       driver_sysfs_add(dev);
+       return ret;
 }

 /**
@@ -503,16 +512,19 @@ 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-3.5-rc6/include/linux/device.h
===================================================================
--- linux-3.5-rc6.orig/include/linux/device.h   2012-07-13 15:10:46.137790406 
+0900
+++ linux-3.5-rc6/include/linux/device.h        2012-07-13 15:12:41.371349562 
+0900
@@ -827,7 +827,7 @@ 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);

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