From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1FB1FC55822 for ; Tue, 4 Aug 2026 13:13:38 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id B0A7010EA4D; Tue, 4 Aug 2026 13:13:37 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=intel.com header.i=@intel.com header.b="Q87ATBFA"; dkim-atps=neutral Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.16]) by gabe.freedesktop.org (Postfix) with ESMTPS id CADBA10EA51; Tue, 4 Aug 2026 13:13:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1785849216; x=1817385216; h=from:to:subject:in-reply-to:references:date:message-id: mime-version; bh=rybi2gi45uqGfa5yrMPOMczdwx7wNC+VlwwLMKCBhbw=; b=Q87ATBFAE6CH7FwID30qTrJ3oi6Kp1O3RcRvP8d65fooHhIbgo7TiH8W xDVqMCPTAo2KB2nAdLNV57T7KRNvd7mrVN7QTVPMG4K5C0ykjjdWxhHsW Q3z3P+Xz0Evk/R6PNT+tEotpKXxNtGyoep2Gdz4QOLwc6FzPAfniFkoAp qnupI5+8MECwvlIkNxagFKLXrf9AxaXmOfXOD/X97HjVwlycMFbNf8wc6 noI2AUlClh26VTEPpaNO94mLCJthnTHbociTdoWMHg0+5Fktfz1qq9YXF vz3oimK6RJ7RS91m2Nfr6F1OnsnKogjEQVaANIPqSBnOrDPgsG+8/Kadq A==; X-CSE-ConnectionGUID: fuxDITwfSPChIhcF5Vpv8Q== X-CSE-MsgGUID: b/YM7dX0S++Ca9qa+/XDFA== X-IronPort-AV: E=McAfee;i="6800,10657,11864"; a="86598227" X-IronPort-AV: E=Sophos;i="6.25,204,1779174000"; d="scan'208";a="86598227" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by orvoesa108.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Aug 2026 06:13:35 -0700 X-CSE-ConnectionGUID: XMyW5Z1hRrOr/tsJXKHLKA== X-CSE-MsgGUID: kxcnGRXETP2+j7OiRh0Y0w== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.25,204,1779174000"; d="scan'208";a="284885289" Received: from kniemiec-mobl1.ger.corp.intel.com (HELO localhost) ([10.245.245.151]) by fmviesa002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 04 Aug 2026 06:13:01 -0700 From: Jani Nikula To: Haram Choi , dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, ville.syrjala@linux.intel.com Subject: Re: [REGRESSION] 7.1: apple-gmux backlight dead on MacBookPro13,3 - PCI bridge left with VGA enable set and VGA 16-bit decode cleared, aliasing legacy VGA I/O over the gmux ports In-Reply-To: <0102019fcb5d411c-e0a555b7-46da-43a1-bd9d-6cb120f58a7f-000000@eu-west-1.amazonses.com> Organization: Intel Finland Oy - BIC 0357606-4 - c/o Alberga Business Park, 6 krs Bertel Jungin Aukio 5, 02600 Espoo, Finland References: <0102019fcb5d411c-e0a555b7-46da-43a1-bd9d-6cb120f58a7f-000000@eu-west-1.amazonses.com> Date: Tue, 04 Aug 2026 16:12:58 +0300 Message-ID: <4bf694add4bcd5b6361b3f8a827fb8dab9f250eb@intel.com> MIME-Version: 1.0 Content-Type: text/plain X-BeenThere: intel-gfx@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel graphics driver community testing & development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: intel-gfx-bounces@lists.freedesktop.org Sender: "Intel-gfx" On Tue, 04 Aug 2026, Haram Choi wrote: > I think I have found the commit. It is not in drivers/pci at all, and > my previous suspicion of 94555ea9a048 was wrong. Apologies to Simon > for the noise. > > The regression is: > > cc6ed470caa2 ("drm/i915/vga: Avoid VGA arbiter during > intel_vga_disable() for iGPUs") > Ville Syrjala , 2025-12-08 Uh, that's a bit of a bummer. As you can see, I've only acked it, because quite honestly, I don't fully understand what's going on, but I fully trust Ville to follow through with any issues it might cause. Like this one. However, Ville's not available for a few weeks now, and the commit also does not revert cleanly anymore. We can either try to hack together some sort of fix/revert, or wait for Ville's input. BR, Jani. -- Jani Nikula, Intel