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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 6698EC432C3 for ; Thu, 14 Nov 2019 18:21:03 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 497FC2072C for ; Thu, 14 Nov 2019 18:21:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727361AbfKNSRy (ORCPT ); Thu, 14 Nov 2019 13:17:54 -0500 Received: from mga03.intel.com ([134.134.136.65]:36355 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727262AbfKNSRv (ORCPT ); Thu, 14 Nov 2019 13:17:51 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Nov 2019 10:17:50 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,304,1569308400"; d="scan'208";a="195123499" Received: from chiahuil-mobl.amr.corp.intel.com (HELO pbossart-mobl3.amr.corp.intel.com) ([10.255.228.77]) by orsmga007.jf.intel.com with ESMTP; 14 Nov 2019 10:17:49 -0800 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 , Pierre-Louis Bossart , Sanyog Kale Subject: [PATCH v3 12/22] soundwire: bus: fix race condition with enumeration_complete signaling Date: Thu, 14 Nov 2019 12:16:52 -0600 Message-Id: <20191114181702.22254-13-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191114181702.22254-1-pierre-louis.bossart@linux.intel.com> References: <20191114181702.22254-1-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 This patch adds the signaling needed for Slave drivers to wait until the enumeration completes so that race conditions when issuing read/write commands are avoided. The calls for wait_for_completion() will be added in codec drivers in follow-up patches. The order between init_completion() and complete() is deterministic, the Slave is marked as UNATTACHED either during a Master-initiated HardReset, or when the hardware detects the Slave no longer reports as ATTACHED. Signed-off-by: Pierre-Louis Bossart --- drivers/soundwire/bus.c | 19 +++++++++++++++++++ drivers/soundwire/slave.c | 1 + 2 files changed, 20 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 9f03a915a09a..e34b5ed534b3 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -637,6 +637,25 @@ static void sdw_modify_slave_status(struct sdw_slave *slave, enum sdw_slave_status status) { mutex_lock(&slave->bus->bus_lock); + + dev_vdbg(&slave->dev, + "%s: changing status slave %d status %d new status %d\n", + __func__, slave->dev_num, slave->status, status); + + if (status == SDW_SLAVE_UNATTACHED) { + dev_dbg(&slave->dev, + "%s: initializing completion for Slave %d\n", + __func__, slave->dev_num); + + init_completion(&slave->enumeration_complete); + + } else if (status == SDW_SLAVE_ATTACHED) { + dev_dbg(&slave->dev, + "%s: signaling completion for Slave %d\n", + __func__, slave->dev_num); + + complete(&slave->enumeration_complete); + } slave->status = status; mutex_unlock(&slave->bus->bus_lock); } diff --git a/drivers/soundwire/slave.c b/drivers/soundwire/slave.c index 15ac89ecae01..76fdfbd8b50d 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -52,6 +52,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->dev.type = &sdw_slave_type; slave->bus = bus; slave->status = SDW_SLAVE_UNATTACHED; + init_completion(&slave->enumeration_complete); slave->dev_num = 0; init_completion(&slave->probe_complete); slave->probed = false; -- 2.20.1