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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 58594C433DF for ; Wed, 24 Jun 2020 08:19:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28F3F2088E for ; Wed, 24 Jun 2020 08:19:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592986776; bh=fgExhjyrAR43tXlRTdI8WWUCluEJes8lAjTFdOgFp4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=Y3A0X+PGul7yFbDqiOa7yxXFcnCcdX6/8ArvRGbBfpI4/e2lFAeUd/qf1BSu/V0PC DM1AOeOPQNEq3skqNjDIau4sjn4rTOuPLyzJcltShFQ06UfN382uYvRIjF7e9q8iz/ JGQPZ+/hmIiHsg+h6bywGN5nDM/UOhliN5yWI0+8= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390314AbgFXITf (ORCPT ); Wed, 24 Jun 2020 04:19:35 -0400 Received: from mail.kernel.org ([198.145.29.99]:39314 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388296AbgFXITf (ORCPT ); Wed, 24 Jun 2020 04:19:35 -0400 Received: from localhost (unknown [171.61.66.58]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5C9982082F; Wed, 24 Jun 2020 08:19:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592986774; bh=fgExhjyrAR43tXlRTdI8WWUCluEJes8lAjTFdOgFp4k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=LxtM6dbYSDQRM+QVzBP+DtFg54XGuBddaQfotfsLmUwsFBddn9lvxwBc1myBWsHhp y1ZpueIOm0Qaf8SQjykmjIMSVc4K2RehGwVwWYrrI+fFS+rDcU/NJvVWkg/av/Ow1d rffA+NB4C05F+x/zJCrKohwnzJTywKbJSxWpUt40= Date: Wed, 24 Jun 2020 13:49:29 +0530 From: Vinod Koul To: Sugar Zhang Cc: Heiko Stuebner , linux-rockchip@lists.infradead.org, Dan Williams , dmaengine@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2 02/13] dmaengine: pl330: Add quirk 'arm,pl330-periph-burst' Message-ID: <20200624081929.GU2324254@vkoul-mobl> References: <1591665267-37713-1-git-send-email-sugar.zhang@rock-chips.com> <1591665267-37713-3-git-send-email-sugar.zhang@rock-chips.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1591665267-37713-3-git-send-email-sugar.zhang@rock-chips.com> Sender: dmaengine-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: dmaengine@vger.kernel.org On 09-06-20, 09:14, Sugar Zhang wrote: > This patch adds the qurik to use busrt transfers only s/busrt/burst > for pl330 controller, even for request with a length of 1. > > Although, the correct way should be: if the peripheral request > length is 1, the peripheral should use SINGLE request, and then > notify the dmac using SINGLE mode by src/dst_maxburst with 1. > > For example, on the Rockchip SoCs, all the peripherals can use > SINGLE or BURST request by setting GRF registers. it is possible > that if these peripheral drivers are used only for Rockchip SoCs. > Unfortunately, it's not, such as dw uart, which is used so widely, > and we can't set src/dst_maxburst according to the SoCs' specific > to compatible with all the other SoCs. > > So, for convenience, all the peripherals are set as BURST request > by default on the Rockchip SoCs. even for request with a length of 1. > the current pl330 driver will perform SINGLE transfer if the client's > maxburst is 1, which still should be working according to chapter 2.6.6 > of datasheet which describe how DMAC performs SINGLE transfers for > a BURST request. unfortunately, it's broken on the Rockchip SoCs, s/unfortunately/Unfortunately > which support only matching transfers, such as BURST transfer for > BURST request, SINGLE transfer for SINGLE request. > > Finaly, we add the quirk to specify pl330 to use burst transfers only. s/Finaly/Finally Below looks fine, pls reorder the series and have binding patch come first and then the use of binding. Below looks fine though -- ~Vinod