Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757907Ab1DZSEq (ORCPT ); Tue, 26 Apr 2011 14:04:46 -0400 Received: from smtpout06.highway.telekom.at ([195.3.96.89]:20319 "EHLO email.aon.at" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1755168Ab1DZSEp (ORCPT ); Tue, 26 Apr 2011 14:04:45 -0400 From: Melchior FRANZ To: linux-kernel@vger.kernel.org Subject: Re: i915 completely unusable in 2.6.38.x Date: Tue, 26 Apr 2011 20:04:42 +0200 User-Agent: KMail/1.13.6 (Linux/2.6.38.4; KDE/4.6.0; x86_64; ; ) References: <4DB53B79.4070704@kernelpanic.ru> <20110425210323.GA23418@kroah.com> <201104260959.53084@rk-nord.at> In-Reply-To: <201104260959.53084@rk-nord.at> Cc: Greg KH , dri-devel@lists.freedesktop.org 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: <201104262004.42776@rk-nord.at> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1441 Lines: 38 * Melchior FRANZ -- Tuesday 26 April 2011: > [https://bugzilla.kernel.org/show_bug.cgi?id=31522] I've replied to this error message, but here again for this audience: The commit that broke all 2.6.38.* releases for my machine is this: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=ba3820ade317ee36e496b9b40d2ec3987dd4aef0 (Takashi Iwai: "drm/i915: Revive combination mode for backlight control"). In 'is_backlight_combination_mode()' INTEL_INFO(dev)->gen equals 4, and the function returns 0x40000000 in "combination mode". In 'intel_panel_get_backlight()' this happens: val = I915_READ(BLC_PWM_CTL) & BACKLIGHT_DUTY_CYCLE_MASK; // val = 0x0b4a if (IS_PINEVIEW(dev)) // false val >>= 1; if (is_backlight_combination_mode(dev)){ u8 lbpc; val &= ~1; // val = 0x0b4a pci_read_config_byte(dev->pdev, PCI_LBPC, &lbpc); // lbpc = 0 val *= lbpc; // val = 0 } The backlight remains off and does also not react to the "brighter" key event. Reverting the patch fixes my system, obviously. m. -- 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/