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 26CAFC43613 for ; Thu, 20 Jun 2019 16:43:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id ED6492089C for ; Thu, 20 Jun 2019 16:43:11 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=nvidia.com header.i=@nvidia.com header.b="YvHD4i52" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732023AbfFTQnK (ORCPT ); Thu, 20 Jun 2019 12:43:10 -0400 Received: from hqemgate14.nvidia.com ([216.228.121.143]:19709 "EHLO hqemgate14.nvidia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726675AbfFTQnJ (ORCPT ); Thu, 20 Jun 2019 12:43:09 -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 09:43:07 -0700 Received: from hqmail.nvidia.com ([172.20.161.6]) by hqpgpgate101.nvidia.com (PGP Universal service); Thu, 20 Jun 2019 09:43:08 -0700 X-PGP-Universal: processed; by hqpgpgate101.nvidia.com on Thu, 20 Jun 2019 09:43:08 -0700 Received: from [10.21.132.148] (10.124.1.5) by HQMAIL107.nvidia.com (172.20.187.13) with Microsoft SMTP Server (TLS) id 15.0.1473.3; Thu, 20 Jun 2019 16:43:06 +0000 Subject: Re: [PATCH] dmaengine: tegra210-adma: fix transfer failure To: Sameer Pujar , , CC: , , , , References: <1561047348-14413-1-git-send-email-spujar@nvidia.com> From: Jon Hunter Message-ID: Date: Thu, 20 Jun 2019 17:43:04 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.0 MIME-Version: 1.0 In-Reply-To: <1561047348-14413-1-git-send-email-spujar@nvidia.com> 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" Content-Language: en-US Content-Transfer-Encoding: 7bit DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=nvidia.com; s=n1; t=1561048987; bh=LRAIEKSTmKQE5qE5AvgXkBeRvVsrbSc0H3EL4SfKT80=; 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-Language: Content-Transfer-Encoding; b=YvHD4i52J9zQIZUxt9GAovH9lWLTS+rhcMlPZQARN+5RyGsSsYDop5vfzL7vj8RmI ihLcP7FE9Jb4/bW5lNAD1VsTleV/xCf/gsFtI6HxK1TRboLXUbfj8axEloRw+wJ0ru YmpaVWMx5YJF68IUz6FlRZplicdZWIFvmGscvmYZaycQeTiPBBc7V80xMihWuIMm+c A9wMFBGw4oY+zbRpW2xlJ4qCD1yZoGc8Ewv03NCwm87h2yqZNbzxbx0mo9gXTVEFrH yJMelnI72Z+BNjN71GOwsKnsH/7cXxycM6EweXT9x2A8dhNg271D2DVFhKbzYJFplC nqDKFGPZhToYQ== Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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? Thanks Jon -- nvpublic