[PATCH] ideapad: Check if acpi already handle backlight power to avoid a page fault
This patch avoid a page fault in the ideapad-laptop extras when
turning the backlight power on or off.
Signed-off-by: Rene Bolldorf <xsecute@googlemail.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>
diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c
index 0c59541..0d94eec 100644
--- a/drivers/platform/x86/ideapad-laptop.c
+++ b/drivers/platform/x86/ideapad-laptop.c
@@ -493,6 +493,8 @@
unsigned long power;
struct backlight_device *blightdev = priv->blightdev;
+ if (!blightdev)
+ return;
if (read_ec_data(ideapad_handle, 0x18, &power))
return;
blightdev->props.power = power ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;