From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753243AbaJFSLJ (ORCPT ); Mon, 6 Oct 2014 14:11:09 -0400 Received: from mail-vc0-f182.google.com ([209.85.220.182]:46937 "EHLO mail-vc0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753047AbaJFSLH (ORCPT ); Mon, 6 Oct 2014 14:11:07 -0400 MIME-Version: 1.0 In-Reply-To: <1412618020-22278-1-git-send-email-sonnyrao@chromium.org> References: <1412618020-22278-1-git-send-email-sonnyrao@chromium.org> Date: Mon, 6 Oct 2014 11:11:05 -0700 X-Google-Sender-Auth: focljBXljfKgEtkZlvKgzdJIqEA Message-ID: Subject: Re: [PATCH] mmc: dw_mmc: Reset DMA before enabling IDMAC From: Doug Anderson To: Sonny Rao Cc: "linux-mmc@vger.kernel.org" , Heiko Stuebner , Seungwon Jeon , Jaehoon Chung , Ulf Hansson , Eddie Cai , Addy Ke , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.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 Sonny, On Mon, Oct 6, 2014 at 10:53 AM, Sonny Rao wrote: > We've already got a reset of DMA after it's done. Add one before we > start DMA too. This fixes a data corruption on Rockchip SoCs which > will get bad data when doing a DMA transfer after doing a PIO transfer. > > We tested this on an Exynos 5800 with HS200 and didn't notice any > difference in sequential read throughput. > > Signed-off-by: Sonny Rao > Signed-off-by: Doug Anderson > --- > drivers/mmc/host/dw_mmc.c | 4 ++++ > 1 file changed, 4 insertions(+) Reviewed-by: Doug Anderson Tested-by: Doug Anderson