platform/x86: fujitsu-laptop: only handle backlight when appropriate

The backlight part of fujitsu-laptop is only used by laptops which are
incapable of using the standard ACPI video interface for handling
brightness changes.  Conversely, on laptops which are capable of using
the latter, no vendor-specific ACPI calls should be made unless
explicitly requested by the user.  Bail out immediately from
acpi_fujitsu_bl_add() unless using the vendor-specific interface was
either explicitly requested by the user or automatically selected by the
kernel.

Signed-off-by: Michał Kępień <kernel@kempniu.pl>
Reviewed-by: Jonathan Woithe <jwoithe@just42.net>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>

diff --git a/drivers/platform/x86/fujitsu-laptop.c b/drivers/platform/x86/fujitsu-laptop.c
index 928778ccc4c16bb4f20e0c6b49a9b1faf3909a9e..5e3e9511caaffefd10c13d36362006454e73c15a 100644 (file)
--- a/drivers/platform/x86/fujitsu-laptop.c
+++ b/drivers/platform/x86/fujitsu-laptop.c
@@ -574,6 +574,9 @@ static int acpi_fujitsu_bl_add(struct acpi_device *device)
        int state = 0;
        int error;
 
+       if (acpi_video_get_backlight_type() != acpi_backlight_vendor)
+               return -ENODEV;
+
        if (!device)
                return -EINVAL;
 
@@ -626,11 +629,9 @@ static int acpi_fujitsu_bl_add(struct acpi_device *device)
                fujitsu_bl->max_brightness = FUJITSU_LCD_N_LEVELS;
        get_lcd_level();
 
-       if (acpi_video_get_backlight_type() == acpi_backlight_vendor) {
-               error = fujitsu_backlight_register();
-               if (error)
-                       return error;
-       }
+       error = fujitsu_backlight_register();
+       if (error)
+               return error;
 
        return 0;
 }