From owner-freebsd-current@FreeBSD.ORG Sat Jan 31 01:02:00 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 1044DD09 for ; Sat, 31 Jan 2015 01:02:00 +0000 (UTC) Received: from mail.wilcox-tech.com (mail.foxkit.us [192.99.209.192]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client CN "mail.wilcox-tech.com", Issuer "mail.wilcox-tech.com" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id A3E1B18F for ; Sat, 31 Jan 2015 01:01:58 +0000 (UTC) Received: (qmail 30335 invoked from network); 31 Jan 2015 01:03:15 -0000 Received: from ip68-13-243-137.ok.ok.cox.net (HELO ?192.168.1.253?) (emyers@wilcox-tech.com@68.13.243.137) by mail.foxkit.us with ESMTPA; 31 Jan 2015 01:03:15 -0000 Message-ID: <54CC2981.3040909@interlinked.me> Date: Fri, 30 Jan 2015 19:01:53 -0600 From: Elizabeth Myers User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: John Baldwin Subject: Re: Questions on adding backlight support for the i915 driver References: <54C883E7.4000300@interlinked.me> <54CBA0A4.30708@FreeBSD.org> <54CC0999.90500@interlinked.me> <3595567.zVLW9tlg0N@ralph.baldwin.cx> In-Reply-To: <3595567.zVLW9tlg0N@ralph.baldwin.cx> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: freebsd-current@freebsd.org 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: Sat, 31 Jan 2015 01:02:00 -0000 On 01/30/15 17:45, John Baldwin wrote: > On Friday, January 30, 2015 04:45:45 PM Elizabeth Myers wrote: >> On 01/30/15 09:17, John Baldwin wrote: >>> Humm. If the code is going to live in the drm driver, then I would >>> start with hanging a sysctl off of the drm device itself. (Each new-bus >>> device_t has a sysctl ctx you can get to hang new nodes off of the >>> device's node.) >> I'm wondering if that's the correct place for it to live. So far it's >> the only real place it *can* live that makes logical sense imho, unless >> anyone has better ideas. >> >> This is awesome. As for upower, it should probably be patched to know >> about other types of brightness sysctls if/when this is implemented. > For now I think hanging it off of the device_t is fine. It can be moved > later if there is an urgent need. However, I suspect that tools like upower > will need updating regardless of where it ends up living. > Now a more interesting question... the raw PCM backlight value used by the hardware means that one can set the backlight to anything between 0 and a specific number. On my system, it's 4882, and yes, there is a subtle difference between the values. Is it best to expose this as a percentage, or just have a read-only sysctl for max values? -- Cheers, Elizabeth