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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A814C4332F for ; Mon, 28 Nov 2022 16:49:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230493AbiK1Qt0 (ORCPT ); Mon, 28 Nov 2022 11:49:26 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40310 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229670AbiK1QtY (ORCPT ); Mon, 28 Nov 2022 11:49:24 -0500 Received: from mga07.intel.com (mga07.intel.com [134.134.136.100]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 51756167F4; Mon, 28 Nov 2022 08:49:23 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669654163; x=1701190163; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=CgPF6MKTnegmRDmcI5KCYgm3Dojtw3BD/LAsoXreVzA=; b=HtF/KqwLsL6qxOspoQuu4/2ZGgGHtzJdzUMY3XrCXkMN3R+bCvU89Xa9 6ttqO6pnFF5OE67aC2r1Z65KxhLxeOUUpTyAxxFDUwdCkWsz2oOog/CBg dy1TDQnJV9zbZ/cmO6M2vHaO0aoDdHRJLxAYYK+HmiLvywq3rGIM/TQtD VkUNwNjQQYDDi6vZ74q7nk/FbXlItTTY+GsXwegiaOtoB15q18TDkxVIJ qd4lldcZD24VI4h3kLLZEdAEQWh43YgyWL+ASxDhjFdORTQbigZl9E6wT fBEYMBoDluwC+A1fTnD/o1GaZdfGVWrCQBPAKiEjmpeSUeHC76QtwsOYg w==; X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="379144205" X-IronPort-AV: E=Sophos;i="5.96,200,1665471600"; d="scan'208";a="379144205" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga105.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 08:49:22 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10545"; a="768104564" X-IronPort-AV: E=Sophos;i="5.96,200,1665471600"; d="scan'208";a="768104564" Received: from kschjaer-mobl.amr.corp.intel.com (HELO [10.212.114.246]) ([10.212.114.246]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Nov 2022 08:49:21 -0800 Message-ID: <5171929e-b750-d2f1-fec9-b34d76c18dcb@linux.intel.com> Date: Mon, 28 Nov 2022 10:49:20 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.4.2 Subject: Re: [PATCH v4] ALSA: core: Fix deadlock when shutdown a frozen userspace Content-Language: en-US To: Ricardo Ribalda , Kai Vehmanen , Jaroslav Kysela , Peter Ujfalusi , Mark Brown , Daniel Baluta , Bard Liao , Takashi Iwai , Ranjani Sridharan , Liam Girdwood Cc: alsa-devel@alsa-project.org, sound-open-firmware@alsa-project.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org References: <20221127-snd-freeze-v4-0-51ca64b7f2ab@chromium.org> From: Pierre-Louis Bossart In-Reply-To: <20221127-snd-freeze-v4-0-51ca64b7f2ab@chromium.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/28/22 07:42, Ricardo Ribalda wrote: > During kexec(), the userspace is frozen. Therefore we cannot wait for it > to complete. > > Avoid running snd_sof_machine_unregister during shutdown. > > This fixes: > > [ 84.943749] Freezing user space processes ... (elapsed 0.111 seconds) done. > [ 246.784446] INFO: task kexec-lite:5123 blocked for more than 122 seconds. > [ 246.819035] Call Trace: > [ 246.821782] > [ 246.824186] __schedule+0x5f9/0x1263 > [ 246.828231] schedule+0x87/0xc5 > [ 246.831779] snd_card_disconnect_sync+0xb5/0x127 > ... > [ 246.889249] snd_sof_device_shutdown+0xb4/0x150 > [ 246.899317] pci_device_shutdown+0x37/0x61 > [ 246.903990] device_shutdown+0x14c/0x1d6 > [ 246.908391] kernel_kexec+0x45/0xb9 > > And: > > [ 246.893222] INFO: task kexec-lite:4891 blocked for more than 122 seconds. > [ 246.927709] Call Trace: > [ 246.930461] > [ 246.932819] __schedule+0x5f9/0x1263 > [ 246.936855] ? fsnotify_grab_connector+0x5c/0x70 > [ 246.942045] schedule+0x87/0xc5 > [ 246.945567] schedule_timeout+0x49/0xf3 > [ 246.949877] wait_for_completion+0x86/0xe8 > [ 246.954463] snd_card_free+0x68/0x89 > ... > [ 247.001080] platform_device_unregister+0x12/0x35 > > Cc: stable@vger.kernel.org > Fixes: 83bfc7e793b5 ("ASoC: SOF: core: unregister clients and machine drivers in .shutdown") > Signed-off-by: Ricardo Ribalda > --- > To: Pierre-Louis Bossart > To: Liam Girdwood > To: Peter Ujfalusi > To: Bard Liao > To: Ranjani Sridharan > To: Kai Vehmanen > To: Daniel Baluta > To: Mark Brown > To: Jaroslav Kysela > To: Takashi Iwai > Cc: sound-open-firmware@alsa-project.org > Cc: alsa-devel@alsa-project.org > Cc: linux-kernel@vger.kernel.org > --- > Changes in v4: > - Do not call snd_sof_machine_unregister from shutdown. > - Link to v3: https://lore.kernel.org/r/20221127-snd-freeze-v3-0-a2eda731ca14@chromium.org > > Changes in v3: > - Wrap pm_freezing in a function > - Link to v2: https://lore.kernel.org/r/20221127-snd-freeze-v2-0-d8a425ea9663@chromium.org > > Changes in v2: > - Only use pm_freezing if CONFIG_FREEZER > - Link to v1: https://lore.kernel.org/r/20221127-snd-freeze-v1-0-57461a366ec2@chromium.org > --- > sound/soc/sof/core.c | 7 ++----- > 1 file changed, 2 insertions(+), 5 deletions(-) > > diff --git a/sound/soc/sof/core.c b/sound/soc/sof/core.c > index 3e6141d03770..9616ba607ded 100644 > --- a/sound/soc/sof/core.c > +++ b/sound/soc/sof/core.c > @@ -475,19 +475,16 @@ EXPORT_SYMBOL(snd_sof_device_remove); > int snd_sof_device_shutdown(struct device *dev) > { > struct snd_sof_dev *sdev = dev_get_drvdata(dev); > - struct snd_sof_pdata *pdata = sdev->pdata; > > if (IS_ENABLED(CONFIG_SND_SOC_SOF_PROBE_WORK_QUEUE)) > cancel_work_sync(&sdev->probe_work); > > /* > - * make sure clients and machine driver(s) are unregistered to force > - * all userspace devices to be closed prior to the DSP shutdown sequence > + * make sure clients are unregistered prior to the DSP shutdown > + * sequence. > */ > sof_unregister_clients(sdev); > > - snd_sof_machine_unregister(sdev, pdata); > - The comment clearly says that we do want all userspace devices to be closed. This was added in 83bfc7e793b5 ("ASoC: SOF: core: unregister clients and machine drivers in .shutdown") precisely to avoid a platform hang if the devices are used after the shutdown completes. So you are not fixing 83bfc7e793b5, just re-adding a problem to fix another one...