Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753348AbbG3OkK (ORCPT ); Thu, 30 Jul 2015 10:40:10 -0400 Received: from mail-wi0-f182.google.com ([209.85.212.182]:38572 "EHLO mail-wi0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751111AbbG3OkH (ORCPT ); Thu, 30 Jul 2015 10:40:07 -0400 Date: Thu, 30 Jul 2015 16:40:02 +0200 From: Daniel Vetter To: Linus Torvalds Cc: "Theodore Ts'o" , intel-gfx , DRI , Daniel Vetter , Mani Nikula , Ander Conselvan de Oliveira , Linux Kernel Mailing List Subject: Re: [REGRESSION] Re: i915 driver crashes on T540p if docking station attached Message-ID: <20150730144002.GY16722@phenom.ffwll.local> Mail-Followup-To: Linus Torvalds , Theodore Ts'o , intel-gfx , DRI , Daniel Vetter , Mani Nikula , Ander Conselvan de Oliveira , Linux Kernel Mailing List References: <20150730004937.GA3133@thunk.org> <20150730013912.GA4068@thunk.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 4.2.0-rc1+ User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1788 Lines: 42 On Wed, Jul 29, 2015 at 10:18:16PM -0700, Linus Torvalds wrote: > drivers/gpu/drm/drm_atomic_helper.c | 8 +++++--- > 1 file changed, 5 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c > index 5b59d5ad7d1c..aac212297b49 100644 > --- a/drivers/gpu/drm/drm_atomic_helper.c > +++ b/drivers/gpu/drm/drm_atomic_helper.c > @@ -230,10 +230,12 @@ update_connector_routing(struct drm_atomic_state *state, int conn_idx) > } > > connector_state->best_encoder = new_encoder; > - idx = drm_crtc_index(connector_state->crtc); > + if (connector_state->crtc) { > + idx = drm_crtc_index(connector_state->crtc); > > - crtc_state = state->crtc_states[idx]; > - crtc_state->mode_changed = true; > + crtc_state = state->crtc_states[idx]; > + crtc_state->mode_changed = true; > + } This shouldn't happen since if it does we ended up stealing the encoder from the connector itself (we do check for connector_state->crtc earlier) and that would be a bug. I haven't figured out a precise theory but my guess is on the best_encoder selection, and indeed dp mst encoder selection seems to have gone belly up in 4.2 with the bisected commit. I have 4 patches in git://people.freedesktop.org/~danvet/drm fixes-stuff but I couldn't test them yet since no dp mst here and I didn't find anything that would ship faster than 1-2 weeks yet. I'll try to get some other people here to test it meanwhile too. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch -- 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/