Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751433AbbBFFTU (ORCPT ); Fri, 6 Feb 2015 00:19:20 -0500 Received: from mail-lb0-f176.google.com ([209.85.217.176]:56672 "EHLO mail-lb0-f176.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750719AbbBFFTT (ORCPT ); Fri, 6 Feb 2015 00:19:19 -0500 MIME-Version: 1.0 In-Reply-To: <1423140859-20074-1-git-send-email-zhouqiao@marvell.com> References: <1423140859-20074-1-git-send-email-zhouqiao@marvell.com> Date: Fri, 6 Feb 2015 13:19:17 +0800 Message-ID: Subject: Re: [PATCH] dma: mmp-tdma: refine dma disable and dma-pos update From: Zhangfei Gao To: Qiao Zhou Cc: "Williams, Dan J" , Vinod Koul , "dmaengine@vger.kernel.org" , LKML Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1002 Lines: 22 On 5 February 2015 at 20:54, Qiao Zhou wrote: > Below are the refinements. > 1. Set DMA abort bit when disabling dma channel. This will clear > the remaining data in dma FIFO, to fix channel-swap issue. > 2. Read DMA HW pointer when updating DMA status. Previously dma > position is calculated by adding one period size in dma interrupt. > This is inaccurate/insufficient for some high-quality audio APP. > Since interrupt bottom half handler has variable schedule delay, > it causes big error when calculating sample delay. Read the actual > HW pointer and feedback can improve the accuracy. > 3. Do some minor code clean. > > Signed-off-by: Qiao Zhou Acked-by: Zhangfei Gao Thanks -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/