From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jon Hunter Subject: Re: [PATCH v2 0/2] Add memcpy support for tegra210-adma Date: Tue, 6 Sep 2016 14:04:20 +0100 Message-ID: <6f45ff6e-5fa7-7aca-154c-85cf235aa62f@nvidia.com> References: <319ca097-4b10-83b9-841c-52adccbb48ad@nvidia.com> <5db4d7db-b1f4-c6af-de56-e8bb13ebc465@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5db4d7db-b1f4-c6af-de56-e8bb13ebc465@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dmitry Osipenko , Nicolin Chen , vinod.koul@intel.com Cc: linux-kernel@vger.kernel.org, linux-tegra@vger.kernel.org, dmaengine@vger.kernel.org, gnurou@gmail.com, thierry.reding@gmail.com, swarren@wwwdotorg.org, ldewangan@nvidia.com List-Id: linux-tegra@vger.kernel.org On 06/09/16 13:03, Dmitry Osipenko wrote: > On 06.09.2016 14:33, Jon Hunter wrote: >> >> On 03/09/16 01:32, Nicolin Chen wrote: >>> This series of patches add memcpy support for tegra210 ADMA engine. >> >> Thanks. Any reason you choose this DMA and not the APB DMA? The APB DMA >> is more of a generic DMA and so for memcpy it would seem to be a good >> choice and it is available on all Tegras not just Tegra210. >> > > Just a small clarification: > > If I'm not mistaken, APB DMA is mem-to-device, while AHB DMA is mem-to-mem. So, > you probably meant AHB and not the APB. Description from the Tegra TRM: "The APB DMA Controller is placed between the AHB Bus and the APB Bus and is a master on both buses. The APB DMA Controller is used for block data transfers from a source location to the destination location. The source may be DRAM or IRAM, and the destination location could be devices placed on APB Bus; or vice versa." Cheers Jon -- nvpublic From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935137AbcIFNEh (ORCPT ); Tue, 6 Sep 2016 09:04:37 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:4978 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933584AbcIFNEa (ORCPT ); Tue, 6 Sep 2016 09:04:30 -0400 X-PGP-Universal: processed; by hqnvupgp08.nvidia.com on Tue, 06 Sep 2016 05:59:37 -0700 Subject: Re: [PATCH v2 0/2] Add memcpy support for tegra210-adma To: Dmitry Osipenko , Nicolin Chen , References: <319ca097-4b10-83b9-841c-52adccbb48ad@nvidia.com> <5db4d7db-b1f4-c6af-de56-e8bb13ebc465@gmail.com> CC: , , , , , , From: Jon Hunter Message-ID: <6f45ff6e-5fa7-7aca-154c-85cf235aa62f@nvidia.com> Date: Tue, 6 Sep 2016 14:04:20 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <5db4d7db-b1f4-c6af-de56-e8bb13ebc465@gmail.com> X-Originating-IP: [10.21.132.106] X-ClientProxiedBy: UKMAIL102.nvidia.com (10.26.138.15) To UKMAIL101.nvidia.com (10.26.138.13) Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 06/09/16 13:03, Dmitry Osipenko wrote: > On 06.09.2016 14:33, Jon Hunter wrote: >> >> On 03/09/16 01:32, Nicolin Chen wrote: >>> This series of patches add memcpy support for tegra210 ADMA engine. >> >> Thanks. Any reason you choose this DMA and not the APB DMA? The APB DMA >> is more of a generic DMA and so for memcpy it would seem to be a good >> choice and it is available on all Tegras not just Tegra210. >> > > Just a small clarification: > > If I'm not mistaken, APB DMA is mem-to-device, while AHB DMA is mem-to-mem. So, > you probably meant AHB and not the APB. Description from the Tegra TRM: "The APB DMA Controller is placed between the AHB Bus and the APB Bus and is a master on both buses. The APB DMA Controller is used for block data transfers from a source location to the destination location. The source may be DRAM or IRAM, and the destination location could be devices placed on APB Bus; or vice versa." Cheers Jon -- nvpublic