From patchwork Wed Jan 15 00:08:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Pierre-Louis Bossart X-Patchwork-Id: 11333007 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 2109913A0 for ; Wed, 15 Jan 2020 00:12:18 +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 ABE0524673 for ; Wed, 15 Jan 2020 00:12:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alsa-project.org header.i=@alsa-project.org header.b="lWDEHBdn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org ABE0524673 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 A768A17CC; Wed, 15 Jan 2020 01:11:27 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz A768A17CC DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1579047135; bh=QhZixX70pHDv0g6/fJdTJTueK06/C4Yw+TA3boz3kFc=; h=From:To:Date:In-Reply-To:References:Cc:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=lWDEHBdnOmpL6GtIUkXjzLA3HOccgGauiHxNlUXFtUXd4mCcVr+PGKgPbucMv0d7G pbxgBgbJX9NyZ86XZSi59l5/Ctm5tdSX7ys+eFeQjnizyUgFij80V7j+m9RUHhdzms e+Ohvbq1tR1k8qBKGWXYh6aME5a2QVOBlKI12uPI= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id C95ABF8023E; Wed, 15 Jan 2020 01:09:49 +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 48B58F8014D; Wed, 15 Jan 2020 01:09:47 +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 mga18.intel.com (mga18.intel.com [134.134.136.126]) (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 E80B7F800B9 for ; Wed, 15 Jan 2020 01:09:40 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz E80B7F800B9 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Jan 2020 16:09:40 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,320,1574150400"; d="scan'208";a="273468548" Received: from emkilgox-mobl2.amr.corp.intel.com (HELO pbossart-mobl3.amr.corp.intel.com) ([10.251.0.151]) by FMSMGA003.fm.intel.com with ESMTP; 14 Jan 2020 16:09:38 -0800 From: Pierre-Louis Bossart To: alsa-devel@alsa-project.org Date: Tue, 14 Jan 2020 18:08:36 -0600 Message-Id: <20200115000844.14695-3-pierre-louis.bossart@linux.intel.com> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200115000844.14695-1-pierre-louis.bossart@linux.intel.com> References: <20200115000844.14695-1-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 02/10] 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 | 20 ++++++++++++++++++++ drivers/soundwire/slave.c | 1 + 2 files changed, 21 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 4980dfd6f3a3..a2267c3a1d2d 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -610,6 +610,26 @@ 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) && + (slave->status == SDW_SLAVE_UNATTACHED)) { + 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 08db0488e02d..e767a78066ee 100644 --- a/drivers/soundwire/slave.c +++ b/drivers/soundwire/slave.c @@ -46,6 +46,7 @@ static int sdw_slave_add(struct sdw_bus *bus, slave->dev.of_node = of_node_get(to_of_node(fwnode)); 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;