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=-16.2 required=3.0 tests=BAYES_00,DATE_IN_PAST_06_12, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT 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 E4C28C433E1 for ; Tue, 18 Aug 2020 10:17:29 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BD880204EA for ; Tue, 18 Aug 2020 10:17:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726728AbgHRKR1 (ORCPT ); Tue, 18 Aug 2020 06:17:27 -0400 Received: from mga04.intel.com ([192.55.52.120]:39352 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726569AbgHRKR0 (ORCPT ); Tue, 18 Aug 2020 06:17:26 -0400 IronPort-SDR: 3qVvRh29vkvtaGcoDcHJ+XWVRZCOxod4unzOSEiLPBGDX6eJehM/0Mf+SXoQG+nRWG5HHebA6+ A9lV/P2ahuDg== X-IronPort-AV: E=McAfee;i="6000,8403,9716"; a="152284286" X-IronPort-AV: E=Sophos;i="5.76,327,1592895600"; d="scan'208";a="152284286" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2020 03:17:26 -0700 IronPort-SDR: +RQdUwcKd0WpF1MV50K77ipSbXSpGk4l5pWDUHQoibQeSGg/cDyEdDflEAxvBYD4/wd4LIkt6S d0ZiwUUXD3Xg== X-IronPort-AV: E=Sophos;i="5.76,327,1592895600"; d="scan'208";a="279363998" Received: from bard-ubuntu.sh.intel.com ([10.239.13.33]) by fmsmga008-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 18 Aug 2020 03:17:22 -0700 From: Bard Liao To: alsa-devel@alsa-project.org, vkoul@kernel.org Cc: vinod.koul@linaro.org, linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, rander.wang@linux.intel.com, ranjani.sridharan@linux.intel.com, hui.wang@canonical.com, pierre-louis.bossart@linux.intel.com, sanyog.r.kale@intel.com, mengdong.lin@intel.com, bard.liao@intel.com Subject: [PATCH] soundwire: cadence: fix race condition between suspend and Slave device alerts Date: Tue, 18 Aug 2020 06:23:40 +0800 Message-Id: <20200817222340.18042-1-yung-chuan.liao@linux.intel.com> X-Mailer: git-send-email 2.17.1 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pierre-Louis Bossart In system suspend stress cases, the SOF CI reports timeouts. The root cause is that an alert is generated while the system suspends. The interrupt handling generates transactions on the bus that will never be handled because the interrupts are disabled in parallel. As a result, the transaction never completes and times out on resume. This error doesn't seem too problematic since it happens in a work queue, and the system recovers without issues. Nevertheless, this race condition should not happen. When doing a system suspend, or when disabling interrupts, we should make sure the current transaction can complete, and prevent new work from being queued. BugLink: https://github.com/thesofproject/linux/issues/2344 Signed-off-by: Pierre-Louis Bossart Reviewed-by: Ranjani Sridharan Reviewed-by: Rander Wang Signed-off-by: Bard Liao --- drivers/soundwire/cadence_master.c | 24 +++++++++++++++++++++++- drivers/soundwire/cadence_master.h | 1 + 2 files changed, 24 insertions(+), 1 deletion(-) diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 24eafe0aa1c3..1330ffc47596 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -791,7 +791,16 @@ irqreturn_t sdw_cdns_irq(int irq, void *dev_id) CDNS_MCP_INT_SLAVE_MASK, 0); int_status &= ~CDNS_MCP_INT_SLAVE_MASK; - schedule_work(&cdns->work); + + /* + * Deal with possible race condition between interrupt + * handling and disabling interrupts on suspend. + * + * If the master is in the process of disabling + * interrupts, don't schedule a workqueue + */ + if (cdns->interrupt_enabled) + schedule_work(&cdns->work); } cdns_writel(cdns, CDNS_MCP_INTSTAT, int_status); @@ -924,6 +933,19 @@ int sdw_cdns_enable_interrupt(struct sdw_cdns *cdns, bool state) slave_state = cdns_readl(cdns, CDNS_MCP_SLAVE_INTSTAT1); cdns_writel(cdns, CDNS_MCP_SLAVE_INTSTAT1, slave_state); } + cdns->interrupt_enabled = state; + + /* + * Complete any on-going status updates before updating masks, + * and cancel queued status updates. + * + * There could be a race with a new interrupt thrown before + * the 3 mask updates below are complete, so in the interrupt + * we use the 'interrupt_enabled' status to prevent new work + * from being queued. + */ + if (!state) + cancel_work_sync(&cdns->work); cdns_writel(cdns, CDNS_MCP_SLAVE_INTMASK0, slave_intmask0); cdns_writel(cdns, CDNS_MCP_SLAVE_INTMASK1, slave_intmask1); diff --git a/drivers/soundwire/cadence_master.h b/drivers/soundwire/cadence_master.h index fdec62b912d3..4d1aab5b5ec2 100644 --- a/drivers/soundwire/cadence_master.h +++ b/drivers/soundwire/cadence_master.h @@ -133,6 +133,7 @@ struct sdw_cdns { bool link_up; unsigned int msg_count; + bool interrupt_enabled; struct work_struct work; -- 2.17.1