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 30803ECAAD8 for ; Fri, 16 Sep 2022 11:05:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232041AbiIPLFB (ORCPT ); Fri, 16 Sep 2022 07:05:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43928 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231752AbiIPLEO (ORCPT ); Fri, 16 Sep 2022 07:04:14 -0400 Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91732A721D for ; Fri, 16 Sep 2022 03:55:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1663325738; x=1694861738; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=fJFUW8+1F9qiAKmSsj0VidfyYyZ0hwH8viyxweFmXBk=; b=hGHu1g0p6IrWSV9vaPaE5O7LyEbn5yKK7BLzJ3mzH4tdoBOzIj9pVClM gd+mPG5kpbjxklfH7SpajuYKSsjF34NkYSsbCEFtAsVMzFLfY00UggtPZ iNUZEHAFP1bsVAnW15bPokfTvGa/9F8cHmpUrQPtYebL+cC7+C6cZot+q 06H6B8R5TjouCRqZIvulJBxM18uuhMqjO/Oi3GCVhbzHEuAs7xJ4+6f7q oqcwUkjTyILTvr0jzRJfRNdqGthM6EBl4WqrczWz5XJEXFCiDCB9S/zO3 ToXy8h4zurg9gwoLB391MIGDLQIn17PbwgpZRdfJ7PYZGSKz8Bixou82e A==; X-IronPort-AV: E=McAfee;i="6500,9779,10471"; a="286007010" X-IronPort-AV: E=Sophos;i="5.93,320,1654585200"; d="scan'208";a="286007010" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2022 03:55:38 -0700 X-IronPort-AV: E=Sophos;i="5.93,320,1654585200"; d="scan'208";a="743298468" Received: from kchan21-mobl1.ger.corp.intel.com (HELO [10.252.61.56]) ([10.252.61.56]) by orsmga004-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 16 Sep 2022 03:55:35 -0700 Message-ID: <0f4154f6-ad5a-22e7-3b95-5a577c1dff47@linux.intel.com> Date: Fri, 16 Sep 2022 12:55:31 +0200 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Firefox/91.0 Thunderbird/91.11.0 Subject: Re: [PATCH] soundwire: cadence: Don't overwrite msg->buf during write commands Content-Language: en-US To: Richard Fitzgerald , vkoul@kernel.org, yung-chuan.liao@linux.intel.com, sanyog.r.kale@intel.com Cc: patches@opensource.cirrus.com, alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org References: <20220916103505.1562210-1-rf@opensource.cirrus.com> From: Pierre-Louis Bossart In-Reply-To: <20220916103505.1562210-1-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 9/16/22 12:35, Richard Fitzgerald wrote: > The buf passed in struct sdw_msg must only be written for a READ, > in that case the RDATA part of the response is the data value of the > register. > > For a write command there is no RDATA, and buf should be assumed to > be const and unmodifable. The original caller should not expect its data > buffer to be corrupted by an sdw_nwrite(). > > Signed-off-by: Richard Fitzgerald Reviewed-by: Pierre-Louis Bossart > --- > drivers/soundwire/cadence_master.c | 9 ++++++--- > 1 file changed, 6 insertions(+), 3 deletions(-) > > diff --git a/drivers/soundwire/cadence_master.c b/drivers/soundwire/cadence_master.c > index be9cd47f31ec..3ef472049980 100644 > --- a/drivers/soundwire/cadence_master.c > +++ b/drivers/soundwire/cadence_master.c > @@ -544,9 +544,12 @@ cdns_fill_msg_resp(struct sdw_cdns *cdns, > return SDW_CMD_IGNORED; > } > > - /* fill response */ > - for (i = 0; i < count; i++) > - msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA, cdns->response_buf[i]); > + if (msg->flags == SDW_MSG_FLAG_READ) { > + /* fill response */ > + for (i = 0; i < count; i++) > + msg->buf[i + offset] = FIELD_GET(CDNS_MCP_RESP_RDATA, > + cdns->response_buf[i]); > + } > > return SDW_CMD_OK; > }