Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752422AbbG3P5y (ORCPT ); Thu, 30 Jul 2015 11:57:54 -0400 Received: from mx2.suse.de ([195.135.220.15]:45436 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750894AbbG3P5x (ORCPT ); Thu, 30 Jul 2015 11:57:53 -0400 Date: Thu, 30 Jul 2015 17:57:49 +0200 Message-ID: From: Takashi Iwai To: "Theodore Ts'o" Cc: Linus Torvalds , intel-gfx , DRI , Daniel Vetter , Mani Nikula , Ander Conselvan de Oliveira , Linux Kernel Mailing List Subject: Re: [Intel-gfx] [REGRESSION] Re: i915 driver crashes on T540p if docking station attached In-Reply-To: <20150730153228.GA15113@thunk.org> References: <20150730004937.GA3133@thunk.org> <20150730013912.GA4068@thunk.org> <20150730144002.GY16722@phenom.ffwll.local> <20150730153228.GA15113@thunk.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI/1.14.6 (Maruoka) FLIM/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL/10.8 Emacs/24.5 (x86_64-suse-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI 1.14.6 - "Maruoka") Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2521 Lines: 57 On Thu, 30 Jul 2015 17:32:28 +0200, Theodore Ts'o wrote: > > On Thu, Jul 30, 2015 at 04:40:02PM +0200, Daniel Vetter wrote: > > 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. > > Well, I just tested Linus's patch and it works. > > BTW, is there any chance that I can suspend my laptop, and then move > it from my docking station at home (where I have a Dell 30" display) > to my docking station at work (where I have a Dell 24" display), and > actually have the new monitor be detected? For at least the past > year, I have to reboot in order to be able to use the external > monitor? This used to work, but it's been a very long-standing > regression. I undrstand that Multi-stream DP is a evil horrible hack, > and supporting it is painful, but this used to work, and it hasn't in > a long time. :-( Relevant with this? https://bugs.freedesktop.org/show_bug.cgi?id=89589 I wanted to check this by myself, too, as the same bug was reported to openSUSE bugzilla, but I had no hardware showing it. Takashi -- 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/