From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753623AbeDMDew (ORCPT ); Thu, 12 Apr 2018 23:34:52 -0400 Received: from mga02.intel.com ([134.134.136.20]:65378 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753469AbeDMDeu (ORCPT ); Thu, 12 Apr 2018 23:34:50 -0400 X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,444,1517904000"; d="scan'208";a="191147358" Date: Fri, 13 Apr 2018 09:09:18 +0530 From: Vinod Koul To: Baolin Wang Cc: Dan Williams , Eric Long , Mark Brown , dmaengine@vger.kernel.org, LKML Subject: Re: [PATCH 4/5] dmaengine: sprd: Add Spreadtrum DMA configuration Message-ID: <20180413033917.GH6014@localhost> References: <0c2b76aba6a49e583f920ae582d6815fa9cc4361.1523346135.git.baolin.wang@linaro.org> <20180411093634.GC6014@localhost> <20180412093735.GF6014@localhost> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 12, 2018 at 07:30:01PM +0800, Baolin Wang wrote: > >> > what does block and transaction len refer to here > >> > >> Our DMA has 3 transfer mode: transaction transfer, block transfer and > >> fragment transfer. One transaction transfer can contain several blocks > >> transfer, and each block can be set proper block step. One block can > >> contain several fragments transfer with proper fragment step. It can > >> generate interrupts when one transaction transfer or block transfer or > >> fragment transfer is completed if user set the interrupt type. So here > >> we should set the length for transaction transfer, block transfer and > >> fragment transfer. > > > > what are the max size these types support? > > These types max size definition: > > #define SPRD_DMA_FRG_LEN_MASK GENMASK(16, 0) > > #define SPRD_DMA_BLK_LEN_MASK GENMASK(16, 0) > > #define SPRD_DMA_TRSC_LEN_MASK GENMASK(27, 0) They are register defines. How many items or bytes do each type of txn support? -- ~Vinod