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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED autolearn=ham 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 76F0BC433EF for ; Fri, 3 Sep 2021 14:13:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56962610A2 for ; Fri, 3 Sep 2021 14:13:24 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349349AbhICOOX (ORCPT ); Fri, 3 Sep 2021 10:14:23 -0400 Received: from mga05.intel.com ([192.55.52.43]:56993 "EHLO mga05.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1349257AbhICOOW (ORCPT ); Fri, 3 Sep 2021 10:14:22 -0400 X-IronPort-AV: E=McAfee;i="6200,9189,10096"; a="304994689" X-IronPort-AV: E=Sophos;i="5.85,265,1624345200"; d="scan'208";a="304994689" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga105.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2021 07:13:22 -0700 X-IronPort-AV: E=Sophos;i="5.85,265,1624345200"; d="scan'208";a="500376060" Received: from achiranj-mobl.gar.corp.intel.com ([10.213.105.90]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 03 Sep 2021 07:13:19 -0700 Message-ID: Subject: Re: Bug: d0e936adbd22 crashes at boot From: Srinivas Pandruvada To: Jens Axboe , LKML , "Rafael J. Wysocki" , Len Brown , inux-pm@vger.kernel.org Date: Fri, 03 Sep 2021 07:13:16 -0700 In-Reply-To: <942f4041-e4e7-1b08-3301-008ab37ff5b8@kernel.dk> References: <942f4041-e4e7-1b08-3301-008ab37ff5b8@kernel.dk> Content-Type: text/plain; charset="UTF-8" User-Agent: Evolution 3.40.0-1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Axboe, Thanks for reporting. On Fri, 2021-09-03 at 07:36 -0600, Jens Axboe wrote: > Hi, > > Booting Linus's tree causes a crash on my laptop, an x1 gen9. This was > a bit > difficult to pin down as it crashes before the display is up, but I > managed > to narrow it down to: > > commit d0e936adbd2250cb03f2e840c6651d18edc22ace > Author: Srinivas Pandruvada > Date:   Thu Aug 19 19:40:06 2021 -0700 > >     cpufreq: intel_pstate: Process HWP Guaranteed change notification > > which crashes with a NULL pointer deref in notify_hwp_interrupt() -> > queue_delayed_work_on(). > > Reverting this change makes the laptop boot fine again. > Does this change fixes your issue? diff --git a/drivers/cpufreq/intel_pstate.c b/drivers/cpufreq/intel_pstate.c index b4ffe6c8a0d0..6a3c6f60ad12 100644 --- a/drivers/cpufreq/intel_pstate.c +++ b/drivers/cpufreq/intel_pstate.c @@ -1650,7 +1650,10 @@ void notify_hwp_interrupt(void) return; cpudata = all_cpu_data[this_cpu]; - schedule_delayed_work_on(this_cpu, &cpudata->hwp_notify_work, msecs_to_jiffies(10)); + if (cpudata) + schedule_delayed_work_on(this_cpu, &cpudata- >hwp_notify_work, msecs_to_jiffies(10)); + else + wrmsrl(MSR_HWP_STATUS, 0); } static void intel_pstate_enable_hwp_interrupt(struct cpudata *cpudata) Thanks, Srinivas