ACPI video: Harden video bus adding.

It is always better to check return values, so add some new checks and
correct existing ones.

v2: Be consistent and don't mix errors from -E* and AE_* namespaces.

Signed-off-by: Igor Murzov <e-mail@date.by>
Signed-off-by: Len Brown <len.brown@intel.com>

1 files changed, 26 insertions, 15 deletions

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index eaef02afc7cf..462486b9f9b2 100644
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -548,27 +548,27 @@ acpi_video_device_EDID(struct acpi_video_device *device,
  *              1.      The system BIOS should NOT automatically control the brightness 
  *                      level of the LCD when the power changes from AC to DC.
  * Return Value:
- *              -1      wrong arg.
+ *              -EINVAL wrong arg.
  */
 
 static int
 acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 {
-        u64 status = 0;
+        acpi_status status;
         union acpi_object arg0 = { ACPI_TYPE_INTEGER };
         struct acpi_object_list args = { 1, &arg0 };
 
 
-        if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1) {
-                status = -1;
-                goto Failed;
-        }
+        if (bios_flag < 0 || bios_flag > 3 || lcd_flag < 0 || lcd_flag > 1)
+                return -EINVAL;
         arg0.integer.value = (lcd_flag << 2) | bios_flag;
         video->dos_setting = arg0.integer.value;
-        acpi_evaluate_object(video->device->handle, "_DOS", &args, NULL);
+        status = acpi_evaluate_object(video->device->handle, "_DOS",
+                &args, NULL);
+        if (ACPI_FAILURE(status))
+                return -EIO;
 
-      Failed:
-        return status;
+        return 0;
 }
 
 /*
@@ -1343,15 +1343,17 @@ static int
 acpi_video_bus_get_devices(struct acpi_video_bus *video,
                            struct acpi_device *device)
 {
-        int status = 0;
+        int status;
         struct acpi_device *dev;
 
-        acpi_video_device_enumerate(video);
+        status = acpi_video_device_enumerate(video);
+        if (status)
+                return status;
 
         list_for_each_entry(dev, &device->children, node) {
 
                 status = acpi_video_bus_get_one_device(dev, video);
-                if (ACPI_FAILURE(status)) {
+                if (status) {
                         printk(KERN_WARNING PREFIX
                                         "Can't attach device\n");
                         continue;
@@ -1653,8 +1655,12 @@ static int acpi_video_bus_add(struct acpi_device *device)
         mutex_init(&video->device_list_lock);
         INIT_LIST_HEAD(&video->video_device_list);
 
-        acpi_video_bus_get_devices(video, device);
-        acpi_video_bus_start_devices(video);
+        error = acpi_video_bus_get_devices(video, device);
+        if (error)
+                goto err_free_video;
+        error = acpi_video_bus_start_devices(video);
+        if (error)
+                goto err_put_video;
 
         video->input = input = input_allocate_device();
         if (!input) {
@@ -1692,14 +1698,19 @@ static int acpi_video_bus_add(struct acpi_device *device)
 
         video->pm_nb.notifier_call = acpi_video_resume;
         video->pm_nb.priority = 0;
-        register_pm_notifier(&video->pm_nb);
+        error = register_pm_notifier(&video->pm_nb);
+        if (error)
+                goto err_unregister_input_dev;
 
         return 0;
 
+ err_unregister_input_dev:
+        input_unregister_device(input);
  err_free_input_dev:
         input_free_device(input);
  err_stop_video:
         acpi_video_bus_stop_devices(video);
+ err_put_video:
         acpi_video_bus_put_devices(video);
         kfree(video->attached_array);
  err_free_video: