From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-0.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 81607C48BE3 for ; Fri, 21 Jun 2019 03:06:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5A1012070B for ; Fri, 21 Jun 2019 03:06:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="jjX0zTNC" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726296AbfFUDGf (ORCPT ); Thu, 20 Jun 2019 23:06:35 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:17833 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725906AbfFUDGe (ORCPT ); Thu, 20 Jun 2019 23:06:34 -0400 Received: from hqpgpgate101.nvidia.com (Not Verified[216.228.121.13]) by hqemgate14.nvidia.com (using TLS: TLSv1.2, DES-CBC3-SHA) id ; Thu, 20 Jun 2019 20:06:32 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 20 Jun 2019 20:06:33 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 20 Jun 2019 20:06:33 -0700 Received: from [10.24.70.43] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Fri, 21 Jun 2019 03:06:29 +0000 Subject: Re: [PATCH] dmaengine: tegra210-adma: fix transfer failure To: Jon Hunter , , CC: , , , , References: <1561047348-14413-1-git-send-email-spujar@nvidia.com> From: Sameer Pujar Message-ID: Date: Fri, 21 Jun 2019 08:36:26 +0530 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:60.0) Gecko/20100101 Thunderbird/60.7.1 MIME-Version: 1.0 In-Reply-To: X-Originating-IP: [10.124.1.5] X-ClientProxiedBy: HQMAIL105.nvidia.com (172.20.187.12) To HQMAIL107.nvidia.com (172.20.187.13) Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-GB DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1561086393; bh=40qWngcJ5jntuve/oNsoItdezzKA7yP0XJAN671D/Fc=; h=X-PGP-Universal:Subject:To:CC:References:From:Message-ID:Date: User-Agent:MIME-Version:In-Reply-To:X-Originating-IP: X-ClientProxiedBy:Content-Type:Content-Transfer-Encoding: Content-Language; b=jjX0zTNCpWzwZOI5kUCnaO+ziNCoL60UwRp4Gpg10j2KAIp4X1bHHGwRjnvugJeuI ppw0PSoFcmoq0amnR8DQeAvCgiQ/9iaYqhiDxDOAoctQWYatWZseJVsGflTjgGGGTc Yi2MOXGddTqDzNT7EG7cje5DxIF3K54kGl5iAMJ6HkJqBHlYWqnnGzzsaaSRL2zm58 cbWNYbc5FVls9IAfYdW3wQ0xcE34FlA0g0X/9JClw6XQSAQ+pT/PR9DRxeNl0vPj40 VL0EXtnx8Eo2ypZA15xalfJCMrHMQR+pGS1dshOQv21B5525dwEicuM3WZoZ4R9EEs Y9UM/nbS9LwcQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 6/20/2019 10:13 PM, Jon Hunter wrote: > On 20/06/2019 17:15, Sameer Pujar wrote: >> From Tegra186 onwards OUTSTANDING_REQUESTS field is added in channel >> configuration register (bits 7:4). ADMA allows a maximum of 8 reads >> to source and that many writes to target memory be outstanding at any >> given point of time. If this field is not programmed, DMA transfers >> fail to happen. > BTW, I am not sure I follow the above. You say a max of 8 reads to the > source, however, the field we are programming can have a value of up to > 15. So does that mean this field should only be programmed with a max of 8? Yes. As per spec. ADMA allows max value of 8. > Thanks > Jon >