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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 052D8C10F13 for ; Thu, 11 Apr 2019 13:48:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C8FA62133D for ; Thu, 11 Apr 2019 13:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726709AbfDKNsP (ORCPT ); Thu, 11 Apr 2019 09:48:15 -0400 Received: from foss.arm.com ([217.140.101.70]:43524 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726145AbfDKNsP (ORCPT ); Thu, 11 Apr 2019 09:48:15 -0400 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 01C0480D; Thu, 11 Apr 2019 06:48:15 -0700 (PDT) Received: from [10.1.196.75] (e110467-lin.cambridge.arm.com [10.1.196.75]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 116B63F68F; Thu, 11 Apr 2019 06:48:13 -0700 (PDT) Subject: Re: [PATCH v2] arm64: dts: rockchip: add rk3399 UART DMAs To: Heiko Stuebner Cc: Katsuhiro Suzuki , linux-rockchip@lists.infradead.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org References: <20190321162244.10080-1-katsuhiro@katsuster.net> <14265087.Gbs4YZABJo@phil> <69d5d0fd-00c3-36ae-596e-1b9f9452a07a@arm.com> <2463729.IUJ8mRE5Ts@phil> From: Robin Murphy Message-ID: <8d164cfe-c345-aa45-aaf3-11983f9142e5@arm.com> Date: Thu, 11 Apr 2019 14:48:12 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.6.1 MIME-Version: 1.0 In-Reply-To: <2463729.IUJ8mRE5Ts@phil> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-GB Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/04/2019 13:46, Heiko Stuebner wrote: > Hi Robin, > > Am Samstag, 30. März 2019, 00:24:16 CEST schrieb Robin Murphy: >> On 2019-03-27 12:00 pm, Heiko Stuebner wrote: >>> Hi, >>> >>> Am Dienstag, 26. März 2019, 14:49:16 CET schrieb Katsuhiro Suzuki: >>>> Hello Robin, >>>> >>>> Sorry for inconvenience. Since I don't adhere enabling DMA for UARTs, >>>> please revert my patch if you need. >>> >>> I've dropped the patch from my queue now. >>> >>>> BTW, there are DMA properties in RK3328 device-tree like as this patch. >>>> RK3328 UART DMA could not work correctly too...?? >>> >>> I remember Rockcihip dma-controllers having issues with burst-sizes >>> and flushing (there is a no-flushp option in pl330), so it's >>> possible that all share the same error up to rk3399 and rk3328 >>> >>> But so far no-one has shouted regarding the rk3328. >> >> Let me be the first, then, I guess :) >> >> I found an easy way to observe the problem on my 3399, and I've just >> fired up my 3328 box with a 5.0 distro kernel to find that it behaves >> the same. Basically just dump a large pile of text into 'less' on the >> serial console, and scroll through line-by-line - certain lines get >> dropped except for a few characters at the end. >> >> I'll see if I can narrow it down a bit, starting with trying >> broken-flushp... > > did you manage to find time for that test you wanted to do? Sadly not - I got somewhat distracted by the ethernet thing, and since then I've had too much else going on to follow up on any of my 'for fun' projects :( If it helps, from a quick look based on what I can remember off-hand, Rockchip UARTs in general have probably been using DMA since 4.19 with d8095f94e195 ("dmaengine: add support for reporting pause and resume separately"). Robin.