Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753097Ab1EQI6o (ORCPT ); Tue, 17 May 2011 04:58:44 -0400 Received: from smtpout06.highway.telekom.at ([195.3.96.89]:43573 "EHLO email.aon.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752068Ab1EQI6n (ORCPT ); Tue, 17 May 2011 04:58:43 -0400 From: Melchior FRANZ To: Michael Chang Subject: Re: i915/kms/backlight-combo mode problem Date: Tue, 17 May 2011 10:58:18 +0200 User-Agent: KMail/1.13.7 (Linux/2.6.38.6; KDE/4.6.3; x86_64; ; ) Cc: Takashi Iwai , linux-kernel@vger.kernel.org, Joey Lee , chris@chris-wilson.co.uk, dri-devel@lists.freedesktop.org References: <201105161421.52451@rk-nord.at> In-Reply-To: X-Fingerprint: 9FFB C079 5B78 4F27 099C C6C6 7399 02D1 919B D903 X-PGP: http://members.aon.at/mfranz/melchior.franz MIME-Version: 1.0 Content-Type: Text/Plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Message-Id: <201105171058.21652@rk-nord.at> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2889 Lines: 70 * Michael Chang -- Tuesday 17 May 2011: [LBPC] > You can know your LPBC value by: > $ lspci -xxx -s 00:02.0 | awk '/^f0:/ {print $6}' > > And alter it's value via setpci (assuming set it to max) > $ setpci -s 00:02.0 F4.B=ff > > I assume you've tried this .. as you report setpci works for you. :) Ahh, yes, indeed. This lspci line (almost) always shows a value that corresponds with the actual backlight brightness, and both lines work with and without acpi_osi=Linux. (Whereas adjustment via keys only works *with* acpi_osi=Linux.) (Tested with 2.6.39-rc7/bd1a643e10) > Could you help to get the LPBC value in the initial dark condition? If > it's not corresponds to 255, maybe something sneaks and changes it but > not logged. Initially (with acpi_osi=Linux) LPBC=0xff. After "brightness down" it's 0x19, and after then pressing "brightness up" it's 0x01. The lowest value I can achieve after pressing "brightness down" a few times is 0xe5, the highest is 0x01. Neither 0xff nor 0x00 can be reached via keys, but can (most of the time -- see below!) be set with the setpci line and give the expected results, backlight off and fully on. ("display toggle" has no effect on LBPC, btw.) Setting 0xFF doesn't always turn the backlight off, though! If LBPC is at the (key) maximum 0x01, then setting 0xFF via setpci changes only the LBPC value as shown by lspci, but the backlight isn't actually turned off! If I then press "backlight darker" once (LBPC=0x19), then setting 0xFF via setpci works again. > 1. $ dmesg -c > 2. Close the lid > 3. Open the lid > 4. $ dmesg > dmesg.lid The results are: [ 188.571040] [drm:intel_panel_set_backlight], set backlight PWM = 736950 [ 188.571048] [drm:is_backlight_combination_mode], BLM_COMBINATION_MODE = 1073741824 [ 188.571054] [drm:is_backlight_combination_mode], BLM_COMBINATION_MODE = 1073741824 [ 188.571059] [drm:intel_panel_get_max_backlight], max backlight PWM = 736950 [ 188.571064] [drm:intel_panel_set_backlight], set backlight max = 736950 [ 188.571069] [drm:intel_panel_set_backlight], set backlight lbpc = 255 [ 188.571075] [drm:intel_panel_set_backlight], set backlight tmp(1) = 189399040 [ 188.571080] [drm:intel_panel_set_backlight], set backlight tmp(2) = 189399040 [ 188.571084] [drm:intel_panel_set_backlight], [ 188.571088] [drm:intel_opregion_asle_intr], non asle set request?? [ 188.571093] set backlight level = 2890 The backlight is off now, as always after closing/reopening the lid, and LPBC=0xff. m. PS: I'd be willing to join an irc.freenode.net channel in case you or anyone else wants quicker ("live") responses to such queries. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/