From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga05.intel.com ([192.55.52.43]:26275 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754888AbcLOJLN (ORCPT ); Thu, 15 Dec 2016 04:11:13 -0500 From: Jani Nikula To: Daniel Vetter Cc: Daniel Vetter , Ville =?utf-8?B?U3lyasOkbMOk?= , Daniel Vetter , Intel Graphics Development , Linus Torvalds , stable@vger.kernel.org, Daniel Vetter Subject: Re: [Intel-gfx] [PATCH] drm/i915: tune down the fast link training vs boot fail In-Reply-To: <20161215074836.5gi66urjvfvrnwvo@phenom.ffwll.local> References: <20161213195414.28923-1-daniel.vetter@ffwll.ch> <20161213202305.GQ31595@intel.com> <20161213223722.xxgheqytlrvsi36d@phenom.ffwll.local> <87bmwer23i.fsf@intel.com> <20161215074836.5gi66urjvfvrnwvo@phenom.ffwll.local> Date: Thu, 15 Dec 2016 11:10:29 +0200 Message-ID: <87twa5pnga.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT Sender: stable-owner@vger.kernel.org List-ID: On Thu, 15 Dec 2016, Daniel Vetter wrote: > On Wed, Dec 14, 2016 at 04:56:33PM +0200, Jani Nikula wrote: >> On Wed, 14 Dec 2016, Daniel Vetter wrote: >> > On Tue, Dec 13, 2016 at 10:23:05PM +0200, Ville Syrjälä wrote: >> >> On Tue, Dec 13, 2016 at 08:54:14PM +0100, Daniel Vetter wrote: >> >> > It's been unfixed since a while and no one is immediately working on >> >> > this. And we have the FIXME already. And now also a task in the DP >> >> > team's backlog. >> >> > >> >> > Cc: Linus Torvalds >> >> > Cc: stable@vger.kernel.org >> >> > Cc: Ville Syrjälä >> >> > References: https://lists.freedesktop.org/archives/intel-gfx/2016-July/101951.html >> >> > Signed-off-by: Daniel Vetter >> >> > --- >> >> > Hi Linus, >> >> > >> >> > Feel free to apply directly in case it annoys too much and you don't >> >> > want to wait for your presents ;-) >> >> > >> >> > Cheers, Daniel >> >> > --- >> >> > drivers/gpu/drm/i915/intel_dp.c | 4 ++-- >> >> > 1 file changed, 2 insertions(+), 2 deletions(-) >> >> > >> >> > diff --git a/drivers/gpu/drm/i915/intel_dp.c b/drivers/gpu/drm/i915/intel_dp.c >> >> > index db75bb924e48..6e875d42642a 100644 >> >> > --- a/drivers/gpu/drm/i915/intel_dp.c >> >> > +++ b/drivers/gpu/drm/i915/intel_dp.c >> >> > @@ -4014,8 +4014,8 @@ intel_dp_check_link_status(struct intel_dp *intel_dp) >> >> > return; >> >> > >> >> > /* FIXME: we need to synchronize this sort of stuff with hardware >> >> > - * readout */ >> >> > - if (WARN_ON_ONCE(!intel_dp->lane_count)) >> >> > + * readout. Currently fast link training doesn't work on boot-up. */ >> >> >> >> s/fast link training/link retraining/ is what I'd put there. >> > >> > Adjusted ... >> >> >> >> I'm a bit sad to hide it but doesn't look like the proper solution is >> >> going to happen any time soon. >> >> >> >> Acked-by: Ville Syrjälä >> > >> > ... and merged since CI seems to approve too ;-) >> >> *sigh* you could've added debug logging at least. Now it's pretty much >> guaranteed nobody will look at this. It's not right to end up here >> without link params. :( > > I've made a JIRA internally to fix this and assigned it to Paul Parenteau > for handling with his DP folks. But I'm happy to also r-b stamp a patch > that adds some debug output here if you want that too. At least I thought > the problem is fairly well-understood, so didn't think this was needed. Oh, okay. Then it's just that *I* didn't understand the problem well. :( BR, Jani. -- Jani Nikula, Intel Open Source Technology Center