Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753151Ab1EQH4M (ORCPT ); Tue, 17 May 2011 03:56:12 -0400 Received: from mail-vw0-f46.google.com ([209.85.212.46]:53809 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752565Ab1EQH4H (ORCPT ); Tue, 17 May 2011 03:56:07 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:cc:content-type; b=p+C83twPw+JPrDV66TFNgqhMsdo3/AzbqJdGWNOJi6BQAEbj155qv/y5kKuGhNo6fL wSuFnpejrg+R2FvNge3NYajzt3TqkdehZ5oO6tvRY7lCdmQBnp+BZSneG0ScHpYoRF85 aNNVa/eY9n628n9/yIszoVKuzRKbAiok5oWLk= MIME-Version: 1.0 In-Reply-To: <201105161421.52451@rk-nord.at> References: <201105101308.24662@rk-nord.at> <201105161421.52451@rk-nord.at> Date: Tue, 17 May 2011 15:56:06 +0800 X-Google-Sender-Auth: pu3ichxgEFvv5Nxed5KSp0fyFQM Message-ID: Subject: Re: i915/kms/backlight-combo mode problem From: Michael Chang To: Melchior FRANZ Cc: Takashi Iwai , linux-kernel@vger.kernel.org, Joey Lee , chris@chris-wilson.co.uk, dri-devel@lists.freedesktop.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2109 Lines: 54 2011/5/16 Melchior FRANZ : > I don't even know what an LBPC is, other than a variable named like that. > So I'd need a hint for how to test that. It resides at your vga adapter's pci configuration space, offset 0xf4. 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. :) >From your new attached log, In booting phase your LPBC is set to 255 and actual brightness is maximum (255*2890=736950). I see no other change after it until manual brightness change. This is a totally reversed to your problem. 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. [ 3.125522] [drm:is_backlight_combination_mode], BLM_COMBINATION_MODE = 1073741824 [ 3.125525] [drm:intel_panel_get_max_backlight], max backlight PWM = 736950 [ 3.125527] [drm:intel_panel_set_backlight], set backlight PWM = 736950 [ 3.125529] [drm:is_backlight_combination_mode], BLM_COMBINATION_MODE = 1073741824 [ 3.125531] [drm:is_backlight_combination_mode], BLM_COMBINATION_MODE = 1073741824 [ 3.125533] [drm:intel_panel_get_max_backlight], max backlight PWM = 736950 [ 3.125535] [drm:intel_panel_set_backlight], set backlight max = 736950 [ 3.125537] [drm:intel_panel_set_backlight], set backlight lbpc = 255 [ 3.125544] [drm:intel_panel_set_backlight], set backlight level = 2890 > Yes, that's the case. (Except that after closing the lid it's off again.) Maybe this is another clue for root cause. Would it be convenient for you to gather the log? 1. $ dmesg -c 2. Close the lid 3. Open the lid 4. $ dmesg > dmesg.lid Thanks a lot, Michael Chang -- 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/