From 910fc79f722372dcc17ff3c53e1f2191c0cf816c Mon Sep 17 00:00:00 2001 From: Rene Bollford Date: Sun, 23 Oct 2011 09:56:42 +0200 Subject: ideapad: Check if acpi already handle backlight power to avoid a page fault commit d4afc7754a60b885b63ef23fd194984e2d53a4e6 upstream. This patch avoid a page fault in the ideapad-laptop extras when turning the backlight power on or off. Signed-off-by: Rene Bolldorf Signed-off-by: Matthew Garrett Signed-off-by: Jonathan Nieder Tested-by: Artem X Signed-off-by: Greg Kroah-Hartman --- drivers/platform/x86/ideapad-laptop.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/platform/x86/ideapad-laptop.c b/drivers/platform/x86/ideapad-laptop.c index 0c595410e788..0d94eec00f4d 100644 --- a/drivers/platform/x86/ideapad-laptop.c +++ b/drivers/platform/x86/ideapad-laptop.c @@ -493,6 +493,8 @@ static void ideapad_backlight_notify_power(struct ideapad_private *priv) 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; -- cgit v1.2.3