From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4BFBCECDFAA for ; Wed, 18 Jul 2018 10:23:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F16752084E for ; Wed, 18 Jul 2018 10:23:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="LitqV/F9" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F16752084E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731046AbeGRLA1 (ORCPT ); Wed, 18 Jul 2018 07:00:27 -0400 Received: from mail-vk0-f65.google.com ([209.85.213.65]:43851 "EHLO mail-vk0-f65.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726865AbeGRLA1 (ORCPT ); Wed, 18 Jul 2018 07:00:27 -0400 Received: by mail-vk0-f65.google.com with SMTP id s17-v6so2197938vke.10; Wed, 18 Jul 2018 03:23:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :cc:content-transfer-encoding; bh=eKz3aEpn6filWjWzCzUm3D6AnFsuTjLJgcZOf66vkWY=; b=LitqV/F9uO7PqFf2fttb5BUo8nMqElIoWd9TQEnrA3MRUUos+5dLtObgpxVoP5QHkf FGan9WhE8BkLARtGrDP5rdkQXCAqyjpv1N4BHk5R6HF/HKE36V2FcRTiQ+DXcazMQf+L QYTujxGFyUI1K9TRPpnfk+xgF77dMjhBNIh+AyMo5SEUcNCce3SUQTNJIbaM7KHiQK1z StIEK0Ww5+xLzUsh6TTSQRoIjbvuyRBBg3RHM5P+3nWHHCjfZ+1hFhi9qCRWejI6u1P/ 4+h04WK2hIAtSnYV21Q+XCtGkUPWgEF+plhA9g+1OvR7NroqwC2bF9Ve1VEv6HLkO+xh OcBQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:cc:content-transfer-encoding; bh=eKz3aEpn6filWjWzCzUm3D6AnFsuTjLJgcZOf66vkWY=; b=Wc7N3h1f1IG2w0h+n0OWRAkSZ9OHalbdmVVzgg6SR6iRlP49iBQNzHFnINAkNS828K p9tw65kg7VudxUcZqTxGVrw0/qWu0S/nX6ZSNqkS1VqpycSpeOJ2lwO4U2KN6JV90msx ws6kcWx23prPGLnKLgLz8OJT+7H00B/KCADBrxyeX58gI/S6Ck2fLdeC3DvCE5ErrxwX 3su9bzCzHqeyxJCtJk/W12qZBQ0YDAviQfi0tKtWJowIYwS3FtT78PTo4a4RLN1JlMKs yneqrsTwE7Rtie+V7wfvXDsA/ObfYFDMLYlazaY1AGBo5n0aJNO2VUS9mksz2d/ofDiq dcbw== X-Gm-Message-State: AOUpUlH9Y5zvMsasZms26Am0ipLmckNjur3ikbMftgU6/1O/Qq9jmNU4 +mxR2NCV3OB4L6UoINUOBUQ1Ezt2LKx+Zh/lpoC2gw== X-Google-Smtp-Source: AAOMgpeEGA4vJ2xPjlWKsaNaVCat2E0WfDs2stkI2oockOaqddZ3X0EjWwDpntNWJr8hSTUBcc+n5hZ+PFkyaajKMaM= X-Received: by 2002:a1f:7d09:: with SMTP id y9-v6mr3007682vkc.15.1531909393544; Wed, 18 Jul 2018 03:23:13 -0700 (PDT) MIME-Version: 1.0 Received: by 2002:a67:2149:0:0:0:0:0 with HTTP; Wed, 18 Jul 2018 03:23:12 -0700 (PDT) In-Reply-To: <20180718100601.GA30600@han> References: <20180718100601.GA30600@han> From: Andy Shevchenko Date: Wed, 18 Jul 2018 13:23:12 +0300 Message-ID: Subject: Re: [FIXED][PATCH] dell-laptop: Fix backlight detection To: =?UTF-8?Q?Damien_Th=C3=A9bault?= Cc: Darren Hart , Matthew Garrett , =?UTF-8?Q?Pali_Roh=C3=A1r?= , Andy Shevchenko , Mario Limonciello , Platform Driver , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 18, 2018 at 1:06 PM, Damien Th=C3=A9bault wro= te: > Fix return code check for "max brightness" ACPI call. > > The dell laptop ACPI video brightness control is not present on dell > laptops anymore, but was present in older kernel versions. > > The code that checks the return value is incorrect since the SMM > refactoring. > > The old code was: > if (buffer->output[0] =3D=3D 0) > > Which was changed to: > ret =3D dell_send_request(...) > if (ret) > > However, dell_send_request() will return 0 if buffer->output[0] =3D=3D 0, > so we must change the check to: > if (ret =3D=3D 0) > > This issue was found on a Dell M4800 laptop, and the fix tested on it > as well. > I have pushed this to my review and testing queue, thanks! But I'm going to push this to Linus this week since it's definitely stable material. > Fixes: 549b4930f057 ("dell-smbios: Introduce dispatcher for SMM calls") > Signed-off-by: Damien Th=C3=A9bault > Tested-by: Damien Th=C3=A9bault > Reviewed-by: Pali Roh=C3=A1r > Reviewed-by: Mario Limonciello > --- > drivers/platform/x86/dell-laptop.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/platform/x86/dell-laptop.c b/drivers/platform/x86/de= ll-laptop.c > index f1fa8612db40..06978c14c83b 100644 > --- a/drivers/platform/x86/dell-laptop.c > +++ b/drivers/platform/x86/dell-laptop.c > @@ -2185,7 +2185,7 @@ static int __init dell_init(void) > dell_fill_request(&buffer, token->location, 0, 0, 0); > ret =3D dell_send_request(&buffer, > CLASS_TOKEN_READ, SELECT_TOKEN_AC= ); > - if (ret) > + if (ret =3D=3D 0) > max_intensity =3D buffer.output[3]; > } > > -- > 2.18.0 > --=20 With Best Regards, Andy Shevchenko