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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 F2C67C43441 for ; Mon, 26 Nov 2018 08:24:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B784E20672 for ; Mon, 26 Nov 2018 08:24:49 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B784E20672 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726336AbeKZTSJ (ORCPT ); Mon, 26 Nov 2018 14:18:09 -0500 Received: from mx2.suse.de ([195.135.220.15]:58672 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726157AbeKZTSJ (ORCPT ); Mon, 26 Nov 2018 14:18:09 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id F35B7AF3F; Mon, 26 Nov 2018 08:24:46 +0000 (UTC) Date: Mon, 26 Nov 2018 09:24:46 +0100 Message-ID: From: Takashi Iwai To: "Alexander Kappner" Cc: , , , , , , , Subject: Re: [snd_hda_intel] snd_hda_intel causes high CPU lockup and system instability if mic disabled in BIOS on Lenovo P50 In-Reply-To: References: 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/26 (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 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 26 Nov 2018 00:17:15 +0100, Alexander Kappner wrote: > > My Lenovo P50 laptop has a BIOS option to disable the microphone. When > this option gets chosen, the snd_hda_intel driver causes high CPU load > on a single kworker thread, spinning on "process_unsol_events", and > system > instability. This behavior occurs from the time that the snd_hda_intel > module is loaded, irrespective of whether anything is attempting to access > the mic. The sound output still works. > > When in this state, the module cannot be removed cleanly; attempting to > remove it (even without rmmod -f) triggers an oops. > > I have attached two exemplary dmesg outputs. Strangely enough, the exact > location of the oops varies, but further up the call chain, I always see > process_unsol_events. > > When the mic is not disabled in the BIOS, the module works stable, > regardless whether or not the mic is muted in ALSA. > > I wasn't able to pinpoint the root cause. Any pointers on where to > start? Much appreciated. Could you load snd-hda-intel driver with probe_only=1 option, and give alsa-info.sh output (run it with --no-upload option)? This should leave only the codec probing without configuring, so we can see the codec widget contents and check the emulator. thanks, Takashi