From owner-freebsd-x11@FreeBSD.ORG Fri May 9 22:19:49 2014 Return-Path: Delivered-To: freebsd-x11@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [8.8.178.115]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by hub.freebsd.org (Postfix) with ESMTPS id 58B70C07 for ; Fri, 9 May 2014 22:19:49 +0000 (UTC) Received: from mail.atelo.org (atelo.org [192.95.27.91]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id 15B0BC38 for ; Fri, 9 May 2014 22:19:48 +0000 (UTC) Received: from coyotlan.atelo.org (ovo.atelo.org [192.168.1.7]); by mail.atelo.org (OpenSMTPD) with ESMTP id 480b5b1d; for ; Fri, 9 May 2014 22:19:00 +0000 (UTC) Received: from localhost (1001@localhost [local]); by localhost (OpenSMTPD) with ESMTPA id 2d17fb65; for ; Fri, 9 May 2014 15:19:26 -0700 (PDT) Date: Fri, 9 May 2014 15:19:26 -0700 From: =?utf-8?B?WMSrY8Oy?= To: freebsd-x11@freebsd.org Subject: Intel i915 backlight Message-ID: <20140509221926.GA2342@coyotlan.atelo.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit User-Agent: Mutt/1.5.23 (2014-03-12) X-BeenThere: freebsd-x11@freebsd.org X-Mailman-Version: 2.1.18 Precedence: list List-Id: X11 on FreeBSD -- maintaining and support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 09 May 2014 22:19:49 -0000 Dear freebsd-x11, I am running /stable/10 (with i915kms and newcons) on a Vaio VPCZ21 with a SandyBridge. Unfortunately backlight is not working out of the box. I played a bit with the existing acpi modules (including acpi_sony and acpi_video), and wrote a bit of code to modify the backlight level, through sony acpi, but it does not seem quite effective. Basically, the (sony) acpi reports 16 backlight levels, iirc, but modifying them does not influence the actual brightness. On linux, backlight level is controlled through the graphic card. So, basically I am investigating how to do so on FreeBSD. I am quite unsure of how it works, probably xbacklight relies on xf86-video-intel. There is some code in sys/dev/drm2/i915/intel_panel.c which looks appropriate to handle the backlight, but I fail to understand how it is called by xorg, for instance. Well, I assume someone here will have a better understanding of all that, and possible on how the intel backlight works, and whether it is only a pwm. For now, I am relying on software xrandr --brightness to set an adequate luminosity, before further investigating the issue. Best, -- Xīcò