thinkpad_acpi: fingers off backlight if video.ko is serving this functionality

Signed-off-by: NThomas Renninger <trenn@suse.de>
Acked-by: NZhang Rui <rui.zhang@intel.com>
Acked-by: NHenrique de Moraes Holschuh <hmh@hmh.eng.br>
Signed-off-by: NAndi Kleen <ak@linux.intel.com>
Signed-off-by: NLen Brown <len.brown@intel.com>

drivers/misc/thinkpad_acpi.c

@@ -4932,16 +4932,25 @@ static int __init brightness_init(struct ibm_init_struct *iibm)
 	 */
 	b = tpacpi_check_std_acpi_brightness_support();
 	if (b > 0) {
-		if (thinkpad_id.vendor == PCI_VENDOR_ID_LENOVO) {
-			printk(TPACPI_NOTICE
-			       "Lenovo BIOS switched to ACPI backlight "
-			       "control mode\n");
-		}
-		if (brightness_enable > 1) {
-			printk(TPACPI_NOTICE
-			       "standard ACPI backlight interface "
-			       "available, not loading native one...\n");
-			return 1;
+
+		if (acpi_video_backlight_support()) {
+			if (brightness_enable > 1) {
+				printk(TPACPI_NOTICE
+				       "Standard ACPI backlight interface "
+				       "available, not loading native one.\n");
+				return 1;
+			} else if (brightness_enable == 1) {
+				printk(TPACPI_NOTICE
+				       "Backlight control force enabled, even if standard "
+				       "ACPI backlight interface is available\n");
+			}
+		} else {
+			if (brightness_enable > 1) {
+				printk(TPACPI_NOTICE
+				       "Standard ACPI backlight interface not "
+				       "available, thinkpad_acpi native "
+				       "brightness control enabled\n");
+			}
 		}
 	}