[PATCH] ACPI : dock: add error handling for acpi_bus_get_device

[Zhouyang Jia]

When acpi_bus_get_device fails, the lack of error-handling code may
cause unexpected results.

This patch adds error-handling code after calling acpi_bus_get_device.

Signed-off-by: Zhouyang Jia <jiazhouyan...@gmail.com>
---
 drivers/acpi/dock.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/acpi/dock.c b/drivers/acpi/dock.c
index e3fc1f0..02fc134 100644
--- a/drivers/acpi/dock.c
+++ b/drivers/acpi/dock.c
@@ -504,7 +504,9 @@ static ssize_t show_docked(struct device *dev,
        struct dock_station *dock_station = dev->platform_data;
        struct acpi_device *adev = NULL;
 
-       acpi_bus_get_device(dock_station->handle, &adev);
+       if (acpi_bus_get_device(dock_station->handle, &adev))
+               return -ENODEV;
+
        return snprintf(buf, PAGE_SIZE, "%u\n", acpi_device_enumerated(adev));
 }
 static DEVICE_ATTR(docked, S_IRUGO, show_docked, NULL);
-- 
2.7.4