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 X-Spam-Level: X-Spam-Status: No, score=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS 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 82B15C4321D for ; Fri, 17 Aug 2018 06:30:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3240121857 for ; Fri, 17 Aug 2018 06:30:43 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3240121857 Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=ti.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726360AbeHQJco (ORCPT ); Fri, 17 Aug 2018 05:32:44 -0400 Received: from lelv0142.ext.ti.com ([198.47.23.249]:58610 "EHLO lelv0142.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726134AbeHQJcn (ORCPT ); Fri, 17 Aug 2018 05:32:43 -0400 Received: from dflxv15.itg.ti.com ([128.247.5.124]) by lelv0142.ext.ti.com (8.15.2/8.15.2) with ESMTP id w7H6UEur079195; Fri, 17 Aug 2018 01:30:14 -0500 Received: from DLEE102.ent.ti.com (dlee102.ent.ti.com [157.170.170.32]) by dflxv15.itg.ti.com (8.14.3/8.13.8) with ESMTP id w7H6UEaD031508; Fri, 17 Aug 2018 01:30:14 -0500 Received: from DLEE108.ent.ti.com (157.170.170.38) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1466.3; Fri, 17 Aug 2018 01:30:14 -0500 Received: from dflp32.itg.ti.com (10.64.6.15) by DLEE108.ent.ti.com (157.170.170.38) with Microsoft SMTP Server (version=TLS1_0, cipher=TLS_RSA_WITH_AES_256_CBC_SHA) id 15.1.1466.3 via Frontend Transport; Fri, 17 Aug 2018 01:30:14 -0500 Received: from [192.168.2.6] (ileax41-snat.itg.ti.com [10.172.224.153]) by dflp32.itg.ti.com (8.14.3/8.13.8) with ESMTP id w7H6UCWv022890; Fri, 17 Aug 2018 01:30:12 -0500 Subject: Re: [RFC] dmaengine: Add metadata_ops for dma_async_tx_descriptor To: Radhey Shyam Pandey , "dan.j.williams@intel.com" , "vkoul@kernel.org" CC: "dmaengine@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "lars@metafoo.de" References: <20180815105704.26498-1-peter.ujfalusi@ti.com> From: Peter Ujfalusi Message-ID: <38aa48ba-5cf9-da12-bef8-b75e22f8b822@ti.com> Date: Fri, 17 Aug 2018 09:30:30 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset="utf-8" Content-Language: en-US Content-Transfer-Encoding: 8bit X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Radhey, On 2018-08-16 16:29, Radhey Shyam Pandey wrote: >> +/** >> + * enum dma_desc_metadata_mode - per descriptor metadata mode types >> supported >> + * @DESC_METADATA_CLIENT - the metadata buffer is allocated/provided by >> the >> + * client driver and it is attached (via the dmaengine_desc_attach_metadata() >> + * helper) to the descriptor. >> + * @DESC_METADATA_EMBEDDED - the metadata buffer is >> allocated/managed by the DMA > Just a thought - We can rename it to DESC_METADATA_ENGINE? > i.e metadata allocation place - > dma client/engine. Sounds good. > >> + * driver. The client driver can ask for the pointer, maximum size and the >> + * currently used size of the metadata and can directly updata or read it. > /s/updata/update > >> + * dmaengine_desc_get_metadata_ptr() and >> dmaengine_desc_set_metadata_len() is >> + * provided as helper functions. > It will be helpful if we add description for both DESC_METADATA_EMBEDDED > modes i.e DMA_DEV_TO_MEM and MEM_TO_DEV types. I think in DEV_TO_MEM > we don't need to set_metadata_len(). Length will provided by DMA engine. I agree, it is better to extend the explanation on the two modes. ... >> +static inline int _desc_check_and_set_metadata_mode( >> + struct dma_async_tx_descriptor *desc, enum >> dma_desc_metadata_mode mode) >> +{ >> + /* Make sure that the metadata mode is not mixed */ >> + if (!desc->desc_metadata_mode) { > Minor nit - we can refactor this code to have failure path early. I don't think it would help readability, to move the failure case first: if (desc->desc_metadata_mode && (desc->desc_metadata_mode != mode)) { return -EINVAL; } else if (!desc->desc_metadata_mode) { if (dmaengine_is_metadata_mode_supported(desc->chan, mode)) desc->desc_metadata_mode = mode; else return -ENOTSUPP; } return 0; > >> + if (dmaengine_is_metadata_mode_supported(desc->chan, >> mode)) >> + desc->desc_metadata_mode = mode; >> + else >> + return -ENOTSUPP; >> + } else if (desc->desc_metadata_mode != mode) { >> + return -EINVAL; >> + } >> + >> + return 0; >> +} - Péter Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki