From patchwork Sun Sep 11 06:09:40 2011 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Ike Panhc X-Patchwork-Id: 114209 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from chlorine.canonical.com (chlorine.canonical.com [91.189.94.204]) by ozlabs.org (Postfix) with ESMTP id 41585B7262 for ; Sun, 11 Sep 2011 16:10:15 +1000 (EST) Received: from localhost ([127.0.0.1] helo=chlorine.canonical.com) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1R2dEg-0006WC-NR; Sun, 11 Sep 2011 06:09:46 +0000 Received: from youngberry.canonical.com ([91.189.89.112]) by chlorine.canonical.com with esmtp (Exim 4.71) (envelope-from ) id 1R2dEf-0006W7-2C for kernel-team@lists.ubuntu.com; Sun, 11 Sep 2011 06:09:45 +0000 Received: from [216.9.106.63] (helo=canonical.com) by youngberry.canonical.com with esmtpsa (TLS1.0:DHE_RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1R2dEe-0004hG-Er for kernel-team@lists.ubuntu.com; Sun, 11 Sep 2011 06:09:45 +0000 From: Ike Panhc To: kernel-team@lists.ubuntu.com Subject: [PATCH] ideapad: Check if acpi already handle backlight power in 'ideapad_backlight_notify_power' to avoid a page fault Date: Sun, 11 Sep 2011 14:09:40 +0800 Message-Id: <1315721380-14355-1-git-send-email-ike.pan@canonical.com> X-Mailer: git-send-email 1.7.5.4 In-Reply-To: <1315721335-14236-1-git-send-email-ike.pan@canonical.com> References: <1315721335-14236-1-git-send-email-ike.pan@canonical.com> X-BeenThere: kernel-team@lists.ubuntu.com X-Mailman-Version: 2.1.13 Precedence: list List-Id: Kernel team discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: kernel-team-bounces@lists.ubuntu.com Errors-To: kernel-team-bounces@lists.ubuntu.com From: Rene Bolldorf 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: Ike Panhc --- drivers/platform/x86/ideapad-laptop.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) 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 @@ 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;