ACPI video: check the return value of acpi_video_device_lcd_set_level

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Acked-by: Matthew Garrett <mjg59@srcf.ucam.org>
Acked-by: Thomas Renninger <trenn@suse.de>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index f0e6eb5..52f52b3 100644 (file)
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -322,12 +322,12 @@ static int acpi_video_get_brightness(struct backlight_device *bd)
 
 static int acpi_video_set_brightness(struct backlight_device *bd)
 {
-       int request_level = bd->props.brightness+2;
+       int request_level = bd->props.brightness + 2;
        struct acpi_video_device *vd =
                (struct acpi_video_device *)bl_get_data(bd);
-       acpi_video_device_lcd_set_level(vd,
-                                       vd->brightness->levels[request_level]);
-       return 0;
+
+       return acpi_video_device_lcd_set_level(vd,
+                               vd->brightness->levels[request_level]);
 }
 
 static struct backlight_ops acpi_backlight_ops = {
@@ -482,23 +482,29 @@ acpi_video_device_lcd_query_levels(struct acpi_video_device *device,
 static int
 acpi_video_device_lcd_set_level(struct acpi_video_device *device, int level)
 {
-       int status = AE_OK;
+       int status;
        union acpi_object arg0 = { ACPI_TYPE_INTEGER };
        struct acpi_object_list args = { 1, &arg0 };
        int state;
 
-
        arg0.integer.value = level;
 
-       if (device->cap._BCM)
-               status = acpi_evaluate_object(device->dev->handle, "_BCM",
-                                             &args, NULL);
+       status = acpi_evaluate_object(device->dev->handle, "_BCM",
+                                     &args, NULL);
+       if (ACPI_FAILURE(status)) {
+               ACPI_ERROR((AE_INFO, "Evaluating _BCM failed"));
+               return -EIO;
+       }
+
        device->brightness->curr = level;
        for (state = 2; state < device->brightness->count; state++)
-               if (level == device->brightness->levels[state])
+               if (level == device->brightness->levels[state]) {
                        device->backlight->props.brightness = state - 2;
+                       return 0;
+               }
 
-       return status;
+       ACPI_ERROR((AE_INFO, "Current brightness invalid"));
+       return -EINVAL;
 }
 
 static int
@@ -1082,13 +1088,12 @@ acpi_video_device_write_brightness(struct file *file,
        /* validate through the list of available levels */
        for (i = 2; i < dev->brightness->count; i++)
                if (level == dev->brightness->levels[i]) {
-                       if (ACPI_SUCCESS
-                           (acpi_video_device_lcd_set_level(dev, level)))
-                               dev->brightness->curr = level;
+                       if (!acpi_video_device_lcd_set_level(dev, level))
+                               return count;
                        break;
                }
 
-       return count;
+       return -EINVAL;
 }
 
 static int acpi_video_device_EDID_seq_show(struct seq_file *seq, void *offset)
@@ -1786,7 +1791,7 @@ acpi_video_switch_brightness(struct acpi_video_device *device, int event)
 
        level_next = acpi_video_get_next_level(device, level_current, event);
 
-       acpi_video_device_lcd_set_level(device, level_next);
+       result = acpi_video_device_lcd_set_level(device, level_next);
 
 out:
        if (result)