From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934204Ab3BSUvr (ORCPT ); Tue, 19 Feb 2013 15:51:47 -0500 Received: from oproxy5-pub.bluehost.com ([67.222.38.55]:60777 "HELO oproxy5-pub.bluehost.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S934167Ab3BSUvq (ORCPT ); Tue, 19 Feb 2013 15:51:46 -0500 Date: Tue, 19 Feb 2013 12:52:17 -0800 From: Jesse Barnes To: Chris Li Cc: linux-kernel@vger.kernel.org, robert.moore@intel.com, feng.tang@intel.com, len.brown@intel.com, daniel.vetter@ffwll.ch, Linus Torvalds Subject: Re: i915 black screen introduced by ACPI changes Message-ID: <20130219125217.6b6f55ff@jbarnes-desktop> In-Reply-To: References: <20130219100849.72d2330b@jbarnes-desktop> X-Mailer: Claws Mail 3.8.0 (GTK+ 2.24.10; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Identified-User: {10642:box514.bluehost.com:virtuous:virtuousgeek.org} {sentby:smtp auth 67.161.37.189 authed with jbarnes@virtuousgeek.org} Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 19 Feb 2013 12:18:45 -0800 Chris Li wrote: > Secondly, the one clue is that, setting "i915.modeset=0" alone will allow > the kernel to boot into X GUI login. It seems that the mode switch alone in > i915 can trigger the black screen. It is consistent with kernel lockup when I > logout of X desktop, where X want to reset the screen. > > Instead of guess which driver were at fault, can you suggest some experiment > to confirm or denial which driver is at fault? Well it definitely sounds i915 related. I was just thinking that if certain bits were routed to the nvidia chip instead of the i915 one, the i915 driver may get confused and panic. For debugging, you could modify the modeset_init function in i915_dma.c and make it return early with an error. You could use that to narrow down which part of init was failing. -- Jesse Barnes, Intel Open Source Technology Center