Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BFE55C64EC4 for ; Mon, 13 Feb 2023 08:31:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229957AbjBMIbi (ORCPT ); Mon, 13 Feb 2023 03:31:38 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229629AbjBMIbf (ORCPT ); Mon, 13 Feb 2023 03:31:35 -0500 Received: from mail-wr1-x435.google.com (mail-wr1-x435.google.com [IPv6:2a00:1450:4864:20::435]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 36E74116 for ; Mon, 13 Feb 2023 00:31:34 -0800 (PST) Received: by mail-wr1-x435.google.com with SMTP id m14so11218287wrg.13 for ; Mon, 13 Feb 2023 00:31:34 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=Gz6xm7NoqnSOUARx/CNCDCfdeCI4cT5lZ/yhcZmlHMg=; b=U5aZIVwzZo8Q4S4+FGo8CVxrW/Nc6LBfif9lyHMNpX0bZmxYinkZwCqhJppeddapMX O+OzsuACDo7fqmYAu+ujfyuYvzxTpzWiwpRDYsH2dnwbfHQhFgQgQDYksm12D/iA7q7B LPwHBUVFJrWs0lUyDoAxVHMSkHPpL1XdJby8J9jBqwDs6osv6Qm+Htdv1UvMpe6IaoT7 dHMxT2NpCisvKDRhpjjvb0Po3rTrDFAgsAUH2fkvRKTzk2SmPyX3nvGnjxKEi1oIxMPS Ll8B6MRsqpFqz3I4gkpc5SYDyebDBA1Xy4LzHoW/4M/zKKAUlMV2p6mxdxsQdp/ljV/D k28w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=Gz6xm7NoqnSOUARx/CNCDCfdeCI4cT5lZ/yhcZmlHMg=; b=wKSs+WKEDst62C8ROedsYfCumyVxDZi09lYeGK+CE3AEp8necWQrMFB9u5c2IfCMgt 4esvffCk8lEeGqNGgJ8uavUUE0rHtwiJxJnQXm4Mk2VgsMG/s5d9uQghr+Z7MzCs20wH LJSHKOhxDeBYerljAS92QEpnoyCkfKdK3EAOZuLqEsnYnEjIyRb9KpARiPl2vdlxbPjm +bu0/GsVBgn2rJ7+Cvrsd4hZSLDHRsiTWQe/Q1IhBQupjE2BS9uSkgzVS6Os4+A/Uvx0 g606aUtGt9DM6hpzS2ClkdpDQ6IFHvfj1mJJx8b+nOclm8feQkno1kRB/xU0buLyzdLb S5TA== X-Gm-Message-State: AO0yUKW+CcZ/4gR69zinCAT+OO2iyVTImnr8kd3cMuVsksuVc+eIN8lt FVFXni6aLYZGeEtGXvAY8JXGpQ== X-Google-Smtp-Source: AK7set+N7x2GSsWP/iFk+wfnyxzr8inqcA6iJA/Kh83OJ6pl7nPyZAAMwrqzG83xPneO0KZeX6Egbw== X-Received: by 2002:adf:ec83:0:b0:2c5:56f6:52ce with SMTP id z3-20020adfec83000000b002c556f652cemr3195215wrn.26.1676277092816; Mon, 13 Feb 2023 00:31:32 -0800 (PST) Received: from [192.168.1.109] ([178.197.216.144]) by smtp.gmail.com with ESMTPSA id h8-20020a5d5048000000b002c54d97b1ecsm5767203wrt.72.2023.02.13.00.31.31 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 13 Feb 2023 00:31:32 -0800 (PST) Message-ID: Date: Mon, 13 Feb 2023 09:31:30 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.7.1 Subject: Re: [PATCH 2/4] soc: aspeed: Add UART DMA support Content-Language: en-US To: ChiaWei Wang , "gregkh@linuxfoundation.org" , "robh+dt@kernel.org" , "krzysztof.kozlowski+dt@linaro.org" , "joel@jms.id.au" , "andrew@aj.id.au" , "jirislaby@kernel.org" , "linux-serial@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" , "linux-aspeed@lists.ozlabs.org" , "linux-kernel@vger.kernel.org" , "openbmc@lists.ozlabs.org" References: <20230210072643.2772-1-chiawei_wang@aspeedtech.com> <20230210072643.2772-3-chiawei_wang@aspeedtech.com> From: Krzysztof Kozlowski In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 13/02/2023 02:50, ChiaWei Wang wrote: >> From: Krzysztof Kozlowski >> Sent: Friday, February 10, 2023 5:14 PM >> >> On 10/02/2023 08:26, Chia-Wei Wang wrote: >>> This driver provides DMA support for AST26xx UART and VUART devices. >>> It is useful to offload CPU overhead while using UART/VUART for binary >>> file transfer. >>> >>> Signed-off-by: Chia-Wei Wang >>> --- >>> drivers/soc/aspeed/Kconfig | 9 + >>> drivers/soc/aspeed/Makefile | 1 + >>> drivers/soc/aspeed/aspeed-udma.c | 447 >> +++++++++++++++++++++++++ >>> include/linux/soc/aspeed/aspeed-udma.h | 34 ++ >> >> NAK. >> >> DMA drivers do not go to soc, but to dma subsystem. > > The UDMA is dedicated only to UART use and is not fully fit to the DMAEngine subsystem. > For example, the suspend/resume operations of common DMA engine are not supported. > After observing certain existing DMA implementation in other soc folders, we put UDMA in the soc/aspeed as well. > If it is not appropriate, should we integrate UDMA into the UART driver or try to make UDMA DMAEngine based? You did not Cc dma folks, so how would I know... Maybe soc is right place if the DMA driver is not suitable for other consumers than UART. Maybe not. Best regards, Krzysztof