From owner-freebsd-current@FreeBSD.ORG Wed Jan 28 09:11:20 2015 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 1041B3D6; Wed, 28 Jan 2015 09:11:20 +0000 (UTC) Received: from mail-ie0-x234.google.com (mail-ie0-x234.google.com [IPv6:2607:f8b0:4001:c03::234]) (using TLSv1 with cipher ECDHE-RSA-RC4-SHA (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id C703C2E0; Wed, 28 Jan 2015 09:11:19 +0000 (UTC) Received: by mail-ie0-f180.google.com with SMTP id rl12so20493753iec.11; Wed, 28 Jan 2015 01:11:19 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type; bh=Kz0yJt4BxUjL2fo8sVspENWK8TkyI/kG9SOCJRgGGQw=; b=kUtpQggXuBhjCcOw6mrScvuONGps2AN1oyQi7k4vMdbm6lSmWGiQTq17IPC0g3KdJH B7ZX2GTalSNHfxPfw7XPTA7GV/oV1bH5Zvwhl1KKWXcm1TUjgWtMKMdy6fIrZmk4BJVF 0QGBPiLX/WAgGmkJPRtavUs6PxM2YlB3za7kScvC5CghExjwTpe6gkIHWeoFoiZDKJ0w XjFNzmEPtqykD0/0RBg/ILzenl9o/mW3V+w4IFiyXR7eOVgPfsjgFfGc0qvypnO4Arzw 6A3lXpEVO/FiL7qTY7hbhJVv6r7gNKHTzuxVr1fbXh1+ecTw1aCzIQiDtrwHOZXMOhnA 0Piw== MIME-Version: 1.0 X-Received: by 10.42.62.71 with SMTP id x7mr2077704ich.61.1422436279139; Wed, 28 Jan 2015 01:11:19 -0800 (PST) Sender: adrian.chadd@gmail.com Received: by 10.36.78.14 with HTTP; Wed, 28 Jan 2015 01:11:19 -0800 (PST) In-Reply-To: References: <000e01d039fb$d5959930$80c0cb90$@Wilcox-Tech.com> <009501d03acb$4f380d70$eda82850$@Wilcox-Tech.com> Date: Wed, 28 Jan 2015 01:11:19 -0800 X-Google-Sender-Auth: JF7os7MLMMSHj9yK7B1AzREzfi4 Message-ID: Subject: Re: drm2 regression: backlight adjustment on ivybridge no longer works From: Adrian Chadd To: Andrew Wilcox , Konstantin Belousov Content-Type: text/plain; charset=UTF-8 Cc: "Ranjan1018 ." <214748mv@gmail.com>, freebsd-current X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.18-1 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 28 Jan 2015 09:11:20 -0000 ugh, so because i can't sleep, I read the Linux i915 history for backlight changes. Turns out if I disable bit 30 in ivb_pch_pwm_override() to register BLC_PWM_PCH_CTL1, the acpi video setting works. The keyboard settings still don't, but I'll worry about that later. Bit 30 in the linux drm code is: #define BLM_PCH_OVERRIDE_ENABLE (1 << 30) The linux dri code doesn't set that for ivybridge - only for broadwell. (also, the linux driver has POSTING_READ() which I'm guessing is to ensure things made it out to the device and have been flushed before doing another IO operation.) I have my (via sysctl) panel backlight control working again. -adrian