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 X-Spam-Level: X-Spam-Status: No, score=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C21E6C433EF for ; Thu, 16 Sep 2021 10:18:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FE0F61165 for ; Thu, 16 Sep 2021 10:18:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236222AbhIPKTU (ORCPT ); Thu, 16 Sep 2021 06:19:20 -0400 Received: from mga07.intel.com ([134.134.136.100]:52280 "EHLO mga07.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234839AbhIPKTT (ORCPT ); Thu, 16 Sep 2021 06:19:19 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10108"; a="286218069" X-IronPort-AV: E=Sophos;i="5.85,298,1624345200"; d="scan'208";a="286218069" Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2021 03:17:58 -0700 X-IronPort-AV: E=Sophos;i="5.85,298,1624345200"; d="scan'208";a="553778537" Received: from djustese-mobl.ger.corp.intel.com (HELO localhost) ([10.249.34.120]) by fmsmga002-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2021 03:17:52 -0700 From: Jani Nikula To: Tvrtko Ursulin , Hugh Dickins , intel-gfx@lists.freedesktop.org Cc: Joonas Lahtinen , Rodrigo Vivi , Vinay Belgaumkar , Michal Wajdeczko , Sujaritha Sundaresan , John Harrison , Daniele Ceraolo Spurio , Matt Roper , Lucas De Marchi , Matthew Brost , Dave Airlie , Daniel Vetter , Pavel Machek , linux-kernel@vger.kernel.org Subject: Re: 5.15-rc1 i915 blank screen booting on ThinkPads In-Reply-To: <9e4c1c68-8d1e-ee2c-99bf-320046130775@linux.intel.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo References: <9e1a6f3b-5e64-be91-ba54-9b5d135ef638@google.com> <9e4c1c68-8d1e-ee2c-99bf-320046130775@linux.intel.com> Date: Thu, 16 Sep 2021 13:17:49 +0300 Message-ID: <87mtocx1rm.fsf@intel.com> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 16 Sep 2021, Tvrtko Ursulin wrote: > Hi, > > On 16/09/2021 05:37, Hugh Dickins wrote: >> Two Lenovo ThinkPads, old T420s (2011), newer X1 Carbon 5th gen (2017): >> i915 working fine on both up to 5.14, but blank screens booting 5.15-rc1, >> kernel crashed in some way. > > T420s could be SandyBridge and X1 Carbon KabyLake. > >> I wanted to say what i915 generations these are, but don't know where >> to look - I don't see it in dmesg, even when DRM_I915_DEBUG enabled. >> >> Possibly relevant: builtin kernels, CONFIG_MODULES off, no initrd. >> >> On the older laptop: >> >> First bisection showed first bad commit >> 41e5c17ebfc2 "drm/i915/guc/slpc: Sysfs hooks for SLPC" >> >> But reverting that still crashed boot with blank screen (and >> reverting the two related commits after it made no difference). >> >> Second bisection, starting from 5.15-rc1 bad and 41e5c17ebfc2 "good", >> but patching it out each time before building, showed first bad commit >> 3ffe82d701a4 "drm/i915/xehp: handle new steering options" >> >> That one did not revert cleanly from 5.15-rc1, but reverting >> 927dfdd09d8c "drm/i915/dg2: Add SQIDI steering" then >> 1705f22c86fb "drm/i915/dg2: Update steering tables" then >> 768fe28dd3dc "drm/i915/xehpsdv: Define steering tables" then >> 3ffe82d701a4 "drm/i915/xehp: handle new steering options" >> worked (there was one very easy fixup needed somewhere). >> >> And 5.15-rc1 with those five reversions boots and runs fine... >> on that older laptop. But reverting those from the kernel on the >> newer laptop did not help at all, still booting with blank screen >> (or no more lines shown after the switch from VGA). Put them back. > > Bisect results sound suspicious since the steering patches do not come > into play on SandyBridge. > >> On the newer laptop, bisection showed first bad commit >> 62eaf0ae217d "drm/i915/guc: Support request cancellation" >> >> And 5.15-rc1 with that reverted boots and runs fine on the newer. > But not on the older laptop? > > Given bisect points to this, it may be worth trying to build both > kernels with CONFIG_DRM_I915_REQUEST_TIMEOUT=0 (no reverts) to see what > happens. But first the logs which I'll ask next. > >> I am hoping that there will be some i915 fixups to come in a later rc! >> May be nothing more than uninitialized variables or NULL pointers. >> You'll probably want more info from me: please ask, but I'm slow. > > Kernel logs with drm.debug=0xe, with the broken black screen state, > would probably answer a lot of questions if you could gather it from > both machines? And for that, I think it's best to file separate bugs at [1] and attach the logs there. It helps keep the info in one place. Thanks. BR, Jani. [1] https://gitlab.freedesktop.org/drm/intel/issues/new > > Regards, > > Tvrtko -- Jani Nikula, Intel Open Source Graphics Center