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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9E2E0C4321E for ; Thu, 1 Dec 2022 20:38:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230472AbiLAUig (ORCPT ); Thu, 1 Dec 2022 15:38:36 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35168 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230338AbiLAUi0 (ORCPT ); Thu, 1 Dec 2022 15:38:26 -0500 Received: from mga04.intel.com (mga04.intel.com [192.55.52.120]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CDAD9A13C3 for ; Thu, 1 Dec 2022 12:38:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1669927105; x=1701463105; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=zELu1XGPksGPNPCJ7usRTQUQut5ZdnmhS1HI4ZrCSWM=; b=GZBTmZpnnYE6kSCVLi6vGQgdoGlzeU88XtC9qC6hbSGxyY4z1/75nH/h 1ApQtOJ+KU2deqGbHzMsdWlUmPttpDp6mHiV0voYYEu5EtJjM+Do7mFPT e5kGFy/mo+LLwbz99xgSAwFSLKIbbauUNFuyUWpg48Dy0Qf+bw7EgLUST lKEbxSWbSe/RYLF8J261NyQORgGGi35Eu+etacKM2l89rg4eVvP2UTn1F 9WEuL/vFUJ6ANJ37nnbtRKfJewPy6LXNm8jqkY4fXqikQMpQkdj4tDn8S CALEQbbNOtK5mV2yJggb2uQmS1qJ5QbkGQ+yDsYj6MIAcE8Rr7nK4bhxW Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="314498372" X-IronPort-AV: E=Sophos;i="5.96,210,1665471600"; d="scan'208";a="314498372" Received: from orsmga002.jf.intel.com ([10.7.209.21]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2022 12:38:04 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10548"; a="644781654" X-IronPort-AV: E=Sophos;i="5.96,210,1665471600"; d="scan'208";a="644781654" Received: from twcarol-mobl.amr.corp.intel.com (HELO [10.212.10.40]) ([10.212.10.40]) by orsmga002-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 01 Dec 2022 12:38:03 -0800 Message-ID: Date: Thu, 1 Dec 2022 11:49:02 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Firefox/102.0 Thunderbird/102.4.2 Subject: Re: [PATCH 1/3] soundwire: cadence: Don't overflow the command FIFOs Content-Language: en-US To: Richard Fitzgerald , vkoul@kernel.org Cc: alsa-devel@alsa-project.org, patches@opensource.cirrus.com, linux-kernel@vger.kernel.org, sanyog.r.kale@intel.com, yung-chuan.liao@linux.intel.com References: <20221201134845.4055907-1-rf@opensource.cirrus.com> <20221201134845.4055907-2-rf@opensource.cirrus.com> From: Pierre-Louis Bossart In-Reply-To: <20221201134845.4055907-2-rf@opensource.cirrus.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/1/22 07:48, Richard Fitzgerald wrote: > The command FIFOs are 8 entries long, so change CDNS_MCP_CMD_LEN to 8. > > CDNS_MCP_CMD_LEN was originally 32, which would lead to cdns_xfer_msg() > writing up to 32 commands into the FIFO, so any message longer than 8 > commands would fail. The change is correct for all instances of SoundWire on Intel platforms. That said, maybe we should capture that the Cadence IP can handle 4/8/16/32 entries - this is a hardware configuration option. We should also mention that so far we have not sent multiple commands so far so the code is only broken when grouping commands. Reviewed-by: Pierre-Louis Bossart > > Signed-off-by: Richard Fitzgerald > Fixes: 2f52a5177caa ("soundwire: cdns: Add cadence library") > --- > drivers/soundwire/cadence_master.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c > index a1de363eba3f..27699f341f2c 100644 > --- a/drivers/soundwire/cadence_master.c > +++ b/drivers/soundwire/cadence_master.c > @@ -127,7 +127,8 @@ MODULE_PARM_DESC(cdns_mcp_int_mask, "Cadence MCP IntMask"); > > #define CDNS_MCP_CMD_BASE 0x80 > #define CDNS_MCP_RESP_BASE 0x80 > -#define CDNS_MCP_CMD_LEN 0x20 > +/* FIFO can hold 8 commands */ > +#define CDNS_MCP_CMD_LEN 8 > #define CDNS_MCP_CMD_WORD_LEN 0x4 > > #define CDNS_MCP_CMD_SSP_TAG BIT(31)