ACPI: video: fix brightness allocation

Fix use of uninitialized device->brightness.

Signed-off-by: Julia Jomantaite <julia.jomantaite@gmail.com>
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Len Brown <len.brown@intel.com>

diff --git a/drivers/acpi/video.c b/drivers/acpi/video.c
index d089c45..64c8893 100644 (file)
--- a/drivers/acpi/video.c
+++ b/drivers/acpi/video.c
@@ -631,6 +631,76 @@ acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
  *     device  : video output device (LCD, CRT, ..)
  *
  *  Return Value:
+ *     Maximum brightness level
+ *
+ *  Allocate and initialize device->brightness.
+ */
+
+static int
+acpi_video_init_brightness(struct acpi_video_device *device)
+{
+       union acpi_object *obj = NULL;
+       int i, max_level = 0, count = 0;
+       union acpi_object *o;
+       struct acpi_video_device_brightness *br = NULL;
+
+       if (!ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
+               ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available "
+                                               "LCD brightness level\n"));
+               goto out;
+       }
+
+       if (obj->package.count < 2)
+               goto out;
+
+       br = kzalloc(sizeof(*br), GFP_KERNEL);
+       if (!br) {
+               printk(KERN_ERR "can't allocate memory\n");
+               goto out;
+       }
+
+       br->levels = kmalloc(obj->package.count * sizeof *(br->levels),
+                               GFP_KERNEL);
+       if (!br->levels)
+               goto out_free;
+
+       for (i = 0; i < obj->package.count; i++) {
+               o = (union acpi_object *)&obj->package.elements[i];
+               if (o->type != ACPI_TYPE_INTEGER) {
+                       printk(KERN_ERR PREFIX "Invalid data\n");
+                       continue;
+               }
+               br->levels[count] = (u32) o->integer.value;
+
+               if (br->levels[count] > max_level)
+                       max_level = br->levels[count];
+               count++;
+       }
+
+       if (count < 2)
+               goto out_free_levels;
+
+       br->count = count;
+       device->brightness = br;
+       ACPI_DEBUG_PRINT((ACPI_DB_INFO, "found %d brightness levels\n", count));
+       kfree(obj);
+       return max_level;
+
+out_free_levels:
+       kfree(br->levels);
+out_free:
+       kfree(br);
+out:
+       device->brightness = NULL;
+       kfree(obj);
+       return 0;
+}
+
+/*
+ *  Arg:
+ *     device  : video output device (LCD, CRT, ..)
+ *
+ *  Return Value:
  *     None
  *
  *  Find out all required AML methods defined under the output
@@ -640,10 +710,7 @@ acpi_video_bus_DOS(struct acpi_video_bus *video, int bios_flag, int lcd_flag)
 static void acpi_video_device_find_cap(struct acpi_video_device *device)
 {
        acpi_handle h_dummy1;
-       int i;
        u32 max_level = 0;
-       union acpi_object *obj = NULL;
-       struct acpi_video_device_brightness *br = NULL;
 
 
        memset(&device->cap, 0, sizeof(device->cap));
@@ -672,53 +739,7 @@ static void acpi_video_device_find_cap(struct acpi_video_device *device)
                device->cap._DSS = 1;
        }
 
-       if (ACPI_SUCCESS(acpi_video_device_lcd_query_levels(device, &obj))) {
-
-               if (obj->package.count >= 2) {
-                       int count = 0;
-                       union acpi_object *o;
-
-                       br = kzalloc(sizeof(*br), GFP_KERNEL);
-                       if (!br) {
-                               printk(KERN_ERR "can't allocate memory\n");
-                       } else {
-                               br->levels = kmalloc(obj->package.count *
-                                                    sizeof *(br->levels), GFP_KERNEL);
-                               if (!br->levels)
-                                       goto out;
-
-                               for (i = 0; i < obj->package.count; i++) {
-                                       o = (union acpi_object *)&obj->package.
-                                           elements[i];
-                                       if (o->type != ACPI_TYPE_INTEGER) {
-                                               printk(KERN_ERR PREFIX "Invalid data\n");
-                                               continue;
-                                       }
-                                       br->levels[count] = (u32) o->integer.value;
-
-                                       if (br->levels[count] > max_level)
-                                               max_level = br->levels[count];
-                                       count++;
-                               }
-                             out:
-                               if (count < 2) {
-                                       kfree(br->levels);
-                                       kfree(br);
-                               } else {
-                                       br->count = count;
-                                       device->brightness = br;
-                                       ACPI_DEBUG_PRINT((ACPI_DB_INFO,
-                                                         "found %d brightness levels\n",
-                                                         count));
-                               }
-                       }
-               }
-
-       } else {
-               ACPI_DEBUG_PRINT((ACPI_DB_INFO, "Could not query available LCD brightness level\n"));
-       }
-
-       kfree(obj);
+       max_level = acpi_video_init_brightness(device);
 
        if (device->cap._BCL && device->cap._BCM && device->cap._BQC && max_level > 0){
                int result;
@@ -1695,6 +1716,8 @@ static void
 acpi_video_switch_brightness(struct acpi_video_device *device, int event)
 {
        unsigned long level_current, level_next;
+       if (!device->brightness)
+               return;
        acpi_video_device_lcd_get_level_current(device, &level_current);
        level_next = acpi_video_get_next_level(device, level_current, event);
        acpi_video_device_lcd_set_level(device, level_next);