From patchwork Tue Jan 26 08:37:44 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Liao, Bard" X-Patchwork-Id: 370662 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=-16.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER, INCLUDES_PATCH, MAILING_LIST_MULTI, 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 0981BC433E0 for ; Tue, 26 Jan 2021 08:40:01 +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 726872065C for ; Tue, 26 Jan 2021 08:40:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 726872065C 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 84E8B17C3; Tue, 26 Jan 2021 09:39:08 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa0.perex.cz 84E8B17C3 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=alsa-project.org; s=default; t=1611650398; bh=x32WrkGUgQciq85+Bq+/F1Jtj/Tu1vtw2eeRIX75M4Q=; h=From:To:Subject:Date:In-Reply-To:References:Cc:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From; b=agAgZLW9SVkWyxs/hbrm/hTZo+OuR2Of8jA0yW5VV4yCbtIQQPRx/qR9k7F999roD SdyooRPLeFmlCq5Vm7h09Paab5zQ68jMp9Z8Az7OEHHec4lXXmWeh5c+xACy+o/74T 3jrp4QFKX/dQ7S3fGO9dU/E9du7Go6cPsnZPzXi8= Received: from alsa1.perex.cz (localhost.localdomain [127.0.0.1]) by alsa1.perex.cz (Postfix) with ESMTP id 758E1F801D8; Tue, 26 Jan 2021 09:38:14 +0100 (CET) Received: by alsa1.perex.cz (Postfix, from userid 50401) id DDE9AF8011C; Tue, 26 Jan 2021 09:38:12 +0100 (CET) Received: from mga01.intel.com (mga01.intel.com [192.55.52.88]) (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 77304F8011C for ; Tue, 26 Jan 2021 09:38:04 +0100 (CET) DKIM-Filter: OpenDKIM Filter v2.11.0 alsa1.perex.cz 77304F8011C IronPort-SDR: dn/IYHZgNoatxcFriReoaXmn29osoonVIsxlepc6wZztg6RuAEEVDSoLnN1Z9q+dFXkyLLLYCB LkwKMqDuVIXg== X-IronPort-AV: E=McAfee;i="6000,8403,9875"; a="198653710" X-IronPort-AV: E=Sophos;i="5.79,375,1602572400"; d="scan'208";a="198653710" Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by fmsmga101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2021 00:38:00 -0800 IronPort-SDR: 8bmCHHC/GO89cpya/Zc4H5EOzdOzGuGl34sxhsdi9m3qpSR2jjbQBU3eFB+cUdn4ihd1DfXyHv 9x56m0kMX5iA== X-IronPort-AV: E=Sophos;i="5.79,375,1602572400"; d="scan'208";a="577731222" Received: from bard-ubuntu.sh.intel.com ([10.239.13.33]) by fmsmga005-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 26 Jan 2021 00:37:57 -0800 From: Bard Liao To: alsa-devel@alsa-project.org, vkoul@kernel.org Subject: [PATCH 1/3] soundwire: bus: clear bus clash interrupt before the mask is enabled Date: Tue, 26 Jan 2021 16:37:44 +0800 Message-Id: <20210126083746.3238-2-yung-chuan.liao@linux.intel.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20210126083746.3238-1-yung-chuan.liao@linux.intel.com> References: <20210126083746.3238-1-yung-chuan.liao@linux.intel.com> Cc: pierre-louis.bossart@linux.intel.com, vinod.koul@linaro.org, gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org, ranjani.sridharan@linux.intel.com, hui.wang@canonical.com, srinivas.kandagatla@linaro.org, jank@cadence.com, sanyog.r.kale@intel.com, rander.wang@linux.intel.com, bard.liao@intel.com 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" The SoundWire specification allows a Slave device to report a bus clash with the in-band interrupt mechanism when it detects a conflict while driving a bitSlot it owns. This can be a symptom of an electrical conflict or a programming error, and it's vital to detect reliably. Unfortunately, on some platforms, bus clashes are randomly reported by Slave devices after a bus reset, with an interrupt status set even before the bus clash interrupt is enabled. These initial spurious interrupts are not relevant and should optionally be filtered out, while leaving the interrupt mechanism enabled to detect 'true' issues. This patch suggests the addition of a Master level quirk to discard such interrupts. The quirk should in theory have been added at the Slave level, but since the problem was detected with different generations of Slave devices it's hard to point to a specific IP. The problem might also be board-dependent and hence dealing with a Master quirk is simpler. Signed-off-by: Bard Liao Reviewed-by: Rander Wang Reviewed-by: Pierre-Louis Bossart --- drivers/soundwire/bus.c | 10 ++++++++++ include/linux/soundwire/sdw.h | 4 ++++ 2 files changed, 14 insertions(+) diff --git a/drivers/soundwire/bus.c b/drivers/soundwire/bus.c index 6e1c988f3845..d394905936e4 100644 --- a/drivers/soundwire/bus.c +++ b/drivers/soundwire/bus.c @@ -1240,6 +1240,7 @@ static int sdw_slave_set_frequency(struct sdw_slave *slave) static int sdw_initialize_slave(struct sdw_slave *slave) { struct sdw_slave_prop *prop = &slave->prop; + int status; int ret; u8 val; @@ -1247,6 +1248,15 @@ static int sdw_initialize_slave(struct sdw_slave *slave) if (ret < 0) return ret; + if (slave->bus->prop.quirks & SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH) { + /* Clear bus clash interrupt before enabling interrupt mask */ + status = sdw_read_no_pm(slave, SDW_SCP_INT1); + if (status & SDW_SCP_INT1_BUS_CLASH) { + dev_warn(&slave->dev, "Bus clash detected before INT mask is enabled\n"); + sdw_write_no_pm(slave, SDW_SCP_INT1, SDW_SCP_INT1_BUS_CLASH); + } + } + /* * Set SCP_INT1_MASK register, typically bus clash and * implementation-defined interrupt mask. The Parity detection diff --git a/include/linux/soundwire/sdw.h b/include/linux/soundwire/sdw.h index f0b01b728640..a2766c3b603d 100644 --- a/include/linux/soundwire/sdw.h +++ b/include/linux/soundwire/sdw.h @@ -405,6 +405,7 @@ struct sdw_slave_prop { * command * @mclk_freq: clock reference passed to SoundWire Master, in Hz. * @hw_disabled: if true, the Master is not functional, typically due to pin-mux + * @quirks: bitmask identifying optional behavior beyond the scope of the MIPI specification */ struct sdw_master_prop { u32 revision; @@ -421,8 +422,11 @@ struct sdw_master_prop { u32 err_threshold; u32 mclk_freq; bool hw_disabled; + u32 quirks; }; +#define SDW_MASTER_QUIRKS_CLEAR_INITIAL_CLASH BIT(0) + int sdw_master_read_prop(struct sdw_bus *bus); int sdw_slave_read_prop(struct sdw_slave *slave);