From patchwork Thu Nov 14 18:16:52 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre-Louis Bossart X-Patchwork-Id: 11244241 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B669A17E0 for ; Thu, 14 Nov 2019 18:26:31 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 3B9A7206F0 for ; Thu, 14 Nov 2019 18:26:31 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="g4KWIdj6" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3B9A7206F0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=alsa-devel-bounces@alsa-project.org Received: from alsa1.perex.cz (alsa1.perex.cz [207.180.221.201]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by alsa0.perex.cz (Postfix) with ESMTPS id CEEA7167D; Thu, 14 Nov 2019 19:25:32 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz CEEA7167D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1573755983; bh=5f73kJ2DEO025QfyIf9Lope4KlEoLnzjLPFfkVvmtE8=; h=From:To:Date:In-Reply-To:References:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=g4KWIdj6NJKsrQzMW3+Gfh0zGXRyQoiQIuNx14zIRr86yVK9tpPvqJ5iWNvUOd0z0 DrlrjKjWy+jadgY/wO4wC3afWiUupa8FJ23eIA6Luw2Io0c+5TguKWtSxRwKwjdFqU oFA8ekXkxFaB75bkd4E3cIHR35rqLdrO1B3p42T0= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id A5FCFF801F7; Thu, 14 Nov 2019 19:18:23 +0100 (CET) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa1.perex.cz (Postfix, from userid 50401) id 3D556F8011E; Thu, 14 Nov 2019 19:17:58 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on alsa1.perex.cz X-Spam-Level: X-Spam-Status: No, score=0.0 required=5.0 tests=SPF_HELO_NONE,SPF_NONE, SURBL_BLOCKED,URIBL_BLOCKED autolearn=disabled version=3.4.0 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by alsa1.perex.cz (Postfix) with ESMTPS id 42EC3F8010D for ; Thu, 14 Nov 2019 19:17:51 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 42EC3F8010D X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga007.jf.intel.com ([10.7.209.58]) by fmsmga103.fm.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 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 Cc: Pierre-Louis Bossart , tiwai@suse.de, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, Ranjani Sridharan , vkoul@kernel.org, broonie@kernel.org, srinivas.kandagatla@linaro.org, jank@cadence.com, slawomir.blauciak@intel.com, Sanyog Kale , Bard liao , Rander Wang Subject: [alsa-devel] [PATCH v3 12/22] soundwire: bus: fix race condition with enumeration_complete signaling X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: "Alsa-devel" 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;