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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id A3697C433EF for ; Fri, 4 Feb 2022 13:24:47 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:Content-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:From:References:CC:To:Subject: MIME-Version:Date:Message-ID:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=9H6G6jUS99UvCnN7vcYfGFj+I8DFH4njS587ghvWKAk=; b=BTQMclKHmCpBU0 7P56IuJRZi1A0Z/R9CJ75d/n5m7AxzaViYQ3d3Wn1IMpOVbcoNj88VNlAJFtuC1TnsBCaXTDrNJtI N9okZ6VYNoXYnAiBw+RmYHL8d//F3oWForfc0rsRzWHbOZcojmE1EU9DLQm+S12c+HVcEXKKSJ/GA 9dpLSQpB1clhp4GCr/NeQbvvW6qnur+282Qfw0H61kcNkSHRk/+4PSxdc0HtC4gw4oRpEybecQyOl vPqj/wqQThhpo5FbOQxUBZOBqTKeZ+SjBYtnFtlEB/uSYXT5zKwTrAcqq7b/ZBkw6U71Vmumut1u1 3EwJ6K1Ab/WF2/xT3XYQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nFyYd-004NPA-Ur; Fri, 04 Feb 2022 13:23:24 +0000 Received: from mx08-00178001.pphosted.com ([91.207.212.93] helo=mx07-00178001.pphosted.com) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nFyYa-004NOc-4Z for linux-arm-kernel@lists.infradead.org; Fri, 04 Feb 2022 13:23:22 +0000 Received: from pps.filterd (m0046661.ppops.net [127.0.0.1]) by mx07-00178001.pphosted.com (8.16.1.2/8.16.1.2) with ESMTP id 2148QohX011944; Fri, 4 Feb 2022 14:23:04 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=foss.st.com; h=message-id : date : mime-version : subject : to : cc : references : from : in-reply-to : content-type : content-transfer-encoding; s=selector1; bh=897N+JwPn9HsR13TZ+mpUH1Tpgf2LXHOh1v74lWbI7w=; b=rMWmSOZjQUwurdCMNkuWKpT9S3b+GmYyH+Tcs0lvO7Jgg+w8iTiuO25GnbHBuofyqj5z iS25mFWBXml+bJa4CntOfU7MnS+bWdP05bEGTjJGbbKftmFT6gAQiXavfW6TVpgLZ7TB /EmywQkiHZeU13/xbsTUYO/7Ut9Wq8UmREeZUhWpUjuN/nMq4F2CcoL3tZQI0PxxxZfJ jRvqwSLNkIZUK+kXdv/Kjj4TlQ0ViEH6AZh2Wu5LFl7T7YlF52O2WkTT3K1FLiU2B9so GvV/Lfy3PPxxsMKoxi6hceKRJuEYjwvnVEZCKbZcvoTgT2hx3WRxIe7xEoQazwqzLbEQ gg== Received: from beta.dmz-eu.st.com (beta.dmz-eu.st.com [164.129.1.35]) by mx07-00178001.pphosted.com (PPS) with ESMTPS id 3e0ejje7de-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Fri, 04 Feb 2022 14:23:04 +0100 Received: from euls16034.sgp.st.com (euls16034.sgp.st.com [10.75.44.20]) by beta.dmz-eu.st.com (STMicroelectronics) with ESMTP id D3BAA10002A; Fri, 4 Feb 2022 14:23:02 +0100 (CET) Received: from Webmail-eu.st.com (sfhdag2node2.st.com [10.75.127.5]) by euls16034.sgp.st.com (STMicroelectronics) with ESMTP id C47AE21FE8A; Fri, 4 Feb 2022 14:23:02 +0100 (CET) Received: from [10.48.0.252] (10.75.127.47) by SFHDAG2NODE2.st.com (10.75.127.5) with Microsoft SMTP Server (TLS) id 15.0.1497.26; Fri, 4 Feb 2022 14:23:02 +0100 Message-ID: Date: Fri, 4 Feb 2022 14:22:56 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101 Thunderbird/91.5.0 Subject: Re: [PATCH 00/16] STM32 configure UART nodes for DMA Content-Language: en-US To: Ahmad Fatoum , Erwan Le Ray CC: Rob Herring , Maxime Coquelin , Manivannan Sadhasivam , Marek Vasut , Marcin Sloniewski , Jagan Teki , , , , , Pengutronix Kernel Team References: <20220203171114.10888-1-erwan.leray@foss.st.com> From: Alexandre TORGUE In-Reply-To: X-Originating-IP: [10.75.127.47] X-ClientProxiedBy: SFHDAG2NODE2.st.com (10.75.127.5) To SFHDAG2NODE2.st.com (10.75.127.5) X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.205,Aquarius:18.0.816,Hydra:6.0.425,FMLib:17.11.62.513 definitions=2022-02-04_05,2022-02-03_01,2021-12-02_01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220204_052320_705114_2026B56E X-CRM114-Status: GOOD ( 27.13 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org Hi Ahmad On 2/3/22 18:25, Ahmad Fatoum wrote: > Hello Erwan, > > On 03.02.22 18:10, Erwan Le Ray wrote: >> Add DMA configuration to UART nodes in stm32mp15x (SOC level) and >> remove it at board level to keep current PIO behavior when needed. >> For stm32-ed1 and stm32-dkx boards, UART4 (console) and UART7 >> (no HW flow control pin available) are kept in PIO mode, while USART3 >> is now configured in DMA mode. >> UART4 (console UART) has to be kept in irq mode, as DMA support for >> console has been removed from the driver by commit e359b4411c28 >> ("serial: stm32: fix threaded interrupt handling"). > > Do I understand correctly that your first patch breaks consoles of > most/all boards, because they will briefly use DMA, which is refused > by the stm32-usart driver and then you add a patch for each board > to fix that breakage? We have two solutions and both have pro/drawbacks. The first one (Erwan ones, can break the boot if the patch is taken "alone". Your proposition avoids this breakage but deletes a non define property (which is a bit weird). However I prefer to keep a functional behavior, and keep Ahmad proposition. Ahmad, just one question, dt-bindings check doesn't complain about it ? Cheers Alex > > Such intermittent breakage makes bisection a hassle. /delete-property/ > is a no-op when the property doesn't exist, so you could move the first > patch to the very end to avoid intermittent breakage. > > I also think that the driver's behavior is a bit harsh. I think it would > be better for the UART driver to print a warning and fall back to > PIO for console instead of outright refusing and rendering the system > silent. That's not mutually exclusive with your patch series here, of course. > > Cheers, > Ahmad > >> >> For other stm32mp15x-based boards, current configuration is kept for >> all UART instances. >> >> Erwan Le Ray (16): >> ARM: dts: stm32: add DMA configuration to UART nodes on stm32mp151 >> ARM: dts: stm32: keep uart4 behavior on stm32mp157c-ed1 >> ARM: dts: stm32: keep uart4 and uart7 behavior on stm32mp15xx-dkx >> ARM: dts: stm32: keep uart4 behavior on icore-stm32mp1-ctouch2 >> ARM: dts: stm32: keep uart4 behavior on icore-stm32mp1-edimm2.2 >> ARM: dts: stm32: keep uart4 behavior on stm32mp157a-iot-box >> ARM: dts: stm32: keep uart nodes behavior on stm32mp1-microdev2.0-of7 >> ARM: dts: stm32: keep uart nodes behavior on stm32mp1-microdev2.0 >> ARM: dts: stm32: keep uart nodes behavior on stm32mp157a-stinger96 >> ARM: dts: stm32: keep uart4 behavior on stm32mp157c-lxa-mc1 >> ARM: dts: stm32: keep uart4 behavior on stm32mp157c-odyssey >> ARM: dts: stm32: keep uart nodes behavior on stm32mp15xx-dhcom-drc02 >> ARM: dts: stm32: keep uart nodes behavior on stm32mp15xx-dhcom-pdk2 >> ARM: dts: stm32: keep uart nodes behavior on stm32mp15xx-dhcom-picoitx >> ARM: dts: stm32: keep uart4 behavior on stm32mp15xx-dhcom-som >> ARM: dts: stm32: keep uart nodes behavior on >> stm32mp15xx-dhcor-avenger96 >> >> arch/arm/boot/dts/stm32mp151.dtsi | 21 +++++++++++++++++++ >> .../stm32mp157a-icore-stm32mp1-ctouch2.dts | 2 ++ >> .../stm32mp157a-icore-stm32mp1-edimm2.2.dts | 2 ++ >> arch/arm/boot/dts/stm32mp157a-iot-box.dts | 2 ++ >> ...157a-microgea-stm32mp1-microdev2.0-of7.dts | 4 ++++ >> ...32mp157a-microgea-stm32mp1-microdev2.0.dts | 4 ++++ >> arch/arm/boot/dts/stm32mp157a-stinger96.dtsi | 6 ++++++ >> arch/arm/boot/dts/stm32mp157c-ed1.dts | 2 ++ >> arch/arm/boot/dts/stm32mp157c-lxa-mc1.dts | 2 ++ >> arch/arm/boot/dts/stm32mp157c-odyssey.dts | 2 ++ >> .../arm/boot/dts/stm32mp15xx-dhcom-drc02.dtsi | 4 ++++ >> arch/arm/boot/dts/stm32mp15xx-dhcom-pdk2.dtsi | 4 ++++ >> .../boot/dts/stm32mp15xx-dhcom-picoitx.dtsi | 4 ++++ >> arch/arm/boot/dts/stm32mp15xx-dhcom-som.dtsi | 2 ++ >> .../boot/dts/stm32mp15xx-dhcor-avenger96.dtsi | 6 ++++++ >> arch/arm/boot/dts/stm32mp15xx-dkx.dtsi | 4 ++++ >> 16 files changed, 71 insertions(+) >> > > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel