From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752212Ab1G2QAa (ORCPT ); Fri, 29 Jul 2011 12:00:30 -0400 Received: from mail-fx0-f46.google.com ([209.85.161.46]:43709 "EHLO mail-fx0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752174Ab1G2QA3 (ORCPT ); Fri, 29 Jul 2011 12:00:29 -0400 MIME-Version: 1.0 In-Reply-To: <1311942777.1536.547.camel@vkoul-udesk3> References: <20110729110525.GG25640@n2100.arm.linux.org.uk> <1311942777.1536.547.camel@vkoul-udesk3> Date: Fri, 29 Jul 2011 08:58:48 -0700 Message-ID: Subject: Re: [PATCH 10/18] dmaengine/amba-pl08x: Get rid of pl08x_pre_boundary() From: viresh kumar To: "Koul, Vinod" Cc: Russell King - ARM Linux , Viresh Kumar , linus.walleij@linaro.org, pratyush.anand@st.com, rajeev-dlh.kumar@st.com, bhupesh.sharma@st.com, shiraz.hashim@st.com, linux-kernel@vger.kernel.org, vipin.kumar@st.com, armando.visconti@st.com, amit.virdi@st.com, vipulkumar.samar@st.com, deepak.sikri@st.com, dan.j.williams@intel.com, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 7/29/11, Koul, Vinod wrote: > On Fri, 2011-07-29 at 12:05 +0100, Russell King - ARM Linux wrote: >> On Fri, Jul 29, 2011 at 04:19:20PM +0530, Viresh Kumar wrote: > Typically in few dmac IPs i know of: > There is max limitation of what a burst length can be for dma, and what > a max transfer length can be. > The dma will push/pull data into peripheral FIFO based on > max_burst_length parameter (note length in dma terminology is always > items not bytes, and one item is usually defined as > transfer_length/src_width). For a transfer (single block or in > multi-block) the dmac will break the transaction into multiple bursts > and based on max_burst_length it will push/pull data to/from FIFO. Also > matching FIFO thresholds with max_burst_length is also important and can > be tuned based on perf/power requirements. > > Sharing my knowledge, hopefully it helps :) > Thanks. It was indeed helpful. :) -- viresh