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=-14.8 required=3.0 tests=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 929FCC0044D for ; Wed, 11 Mar 2020 18:42:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5BDC8206E9 for ; Wed, 11 Mar 2020 18:42:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730959AbgCKSl6 (ORCPT ); Wed, 11 Mar 2020 14:41:58 -0400 Received: from mga18.intel.com ([134.134.136.126]:27194 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730947AbgCKSly (ORCPT ); Wed, 11 Mar 2020 14:41:54 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 11 Mar 2020 11:41:53 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,541,1574150400"; d="scan'208";a="441776253" Received: from fjan-mobl.amr.corp.intel.com (HELO pbossart-mobl3.amr.corp.intel.com) ([10.251.25.157]) by fmsmga005.fm.intel.com with ESMTP; 11 Mar 2020 11:41:51 -0700 From: Pierre-Louis Bossart To: alsa-devel@alsa-project.org Cc: linux-kernel@vger.kernel.org, tiwai@suse.de, broonie@kernel.org, vkoul@kernel.org, gregkh@linuxfoundation.org, jank@cadence.com, srinivas.kandagatla@linaro.org, slawomir.blauciak@intel.com, Bard liao , Rander Wang , Ranjani Sridharan , Hui Wang , Pierre-Louis Bossart , Sanyog Kale Subject: [PATCH 07/16] soundwire: cadence: mask Slave interrupt before stopping clock Date: Wed, 11 Mar 2020 13:41:19 -0500 Message-Id: <20200311184128.4212-8-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200311184128.4212-1-pierre-louis.bossart@linux.intel.com> References: <20200311184128.4212-1-pierre-louis.bossart@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Intel QA reported a very rare case, possibly hardware-dependent, where a Slave can become UNATTACHED during a clock stop sequence, which leads to timeouts and failed suspend sequences. This patch suppresses the handling of all Slave events while this transition happens. The two cases that matter are: a) alerts: if the Slave wants to signal an alert condition, it can do so using the in-band wake, so there's almost no impact with this patch. b) sync loss or imp-def reset: in those cases, bringing back the Slave to functional state requires a complete re-enumeration. It's better to just ignore this case and restart cleanly, rather than attempt a 'clean' suspend. Validation results show the timeouts no longer visible with this patch. GitHub issue: https://github.com/thesofproject/linux/issues/1678 Signed-off-by: Pierre-Louis Bossart --- drivers/soundwire/cadence_master.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c index 02f18ce6b7e7..a4ba57f44c1f 100644 --- a/drivers/soundwire/cadence_master.c +++ b/drivers/soundwire/cadence_master.c @@ -865,6 +865,24 @@ int sdw_cdns_exit_reset(struct sdw_cdns *cdns) } EXPORT_SYMBOL(sdw_cdns_exit_reset); +/** + * sdw_cdns_enable_slave_interrupt() - Enable SDW slave interrupts + * @cdns: Cadence instance + * @state: boolean for true/false + */ +static void cdns_enable_slave_interrupts(struct sdw_cdns *cdns, bool state) +{ + u32 mask; + + mask = cdns_readl(cdns, CDNS_MCP_INTMASK); + if (state) + mask |= CDNS_MCP_INT_SLAVE_MASK; + else + mask &= ~CDNS_MCP_INT_SLAVE_MASK; + + cdns_writel(cdns, CDNS_MCP_INTMASK, mask); +} + /** * sdw_cdns_enable_interrupt() - Enable SDW interrupts * @cdns: Cadence instance @@ -1272,6 +1290,13 @@ int sdw_cdns_clock_stop(struct sdw_cdns *cdns, bool block_wake) return 1; } + /* + * Before entering clock stop we mask the Slave + * interrupts. This helps avoid having to deal with e.g. a + * Slave becoming UNATTACHED while the clock is being stopped + */ + cdns_enable_slave_interrupts(cdns, false); + /* * For specific platforms, it is required to be able to put * master into a state in which it ignores wake-up trials @@ -1349,6 +1374,9 @@ int sdw_cdns_clock_restart(struct sdw_cdns *cdns, bool bus_reset) { int ret; + /* unmask Slave interrupts that were masked when stopping the clock */ + cdns_enable_slave_interrupts(cdns, true); + ret = cdns_clear_bit(cdns, CDNS_MCP_CONTROL, CDNS_MCP_CONTROL_CLK_STOP_CLR); if (ret < 0) { -- 2.20.1