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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 93A72C64ED6 for ; Sun, 26 Feb 2023 13:45:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229504AbjBZNpT (ORCPT ); Sun, 26 Feb 2023 08:45:19 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40016 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbjBZNpS (ORCPT ); Sun, 26 Feb 2023 08:45:18 -0500 Received: from mail-lj1-x22a.google.com (mail-lj1-x22a.google.com [IPv6:2a00:1450:4864:20::22a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79827CDC9 for ; Sun, 26 Feb 2023 05:45:17 -0800 (PST) Received: by mail-lj1-x22a.google.com with SMTP id b10so3847254ljr.0 for ; Sun, 26 Feb 2023 05:45:17 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:from:to:cc:subject:date:message-id:reply-to; bh=JN7moP2awsjlsG1DRZ34+/W1vrYY2zM9tlCpMsaWKeA=; b=brGfVlit8D6j28/QIfydBqY4yGkKBcfq666wdtlD0IhIGF0TRAkkJInXK6qGpG+X0I ikapS+Kqu4Svh0W2swiiioqnSs7oiv20aXvC2ZbaxWXm9TtCdkAa/UUi3afx0O1lLCMi Mdek/HWFhaVUkrmHGCLvsg6K12HddmvDqTv8d7W1tBTB+akukNCifApX3U0glED76Fcj Bt04vkNVJ3kW/faEa2eXJ/QdePJ97btxzNxUuAkguTaHgpH2M9qzc0SQLM+uPnrc01jZ YiAhrNeIwXgcyD+Hlv8LZT3aN/TSdR7yEGdDeGjUvrD6oR6jMidPfn+eQGCbjIwi9gLR 7N9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=mime-version:user-agent:message-id:in-reply-to:date:references :subject:cc:to:from:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=JN7moP2awsjlsG1DRZ34+/W1vrYY2zM9tlCpMsaWKeA=; b=hsCopkTwniI2dqcJJJzBQVEuWdeKY9SJCrXL64UD9VlODhm8nRGI2c3M74JcdxLtYR q9gddmWOk3DkuERvImAb3oQ7qufiDHFYsgYMOT4L2u7G45b3eUTjKNdVaPxDNA3gtw61 LpPfJxbECPySH/3d4/CBBtkTm/IBgYTUmo9sDJrXn9KvfizuLzwgV5wU32vyzRR94sIU VPFDUiEQQO1GvDPZGyOZaxLuAMnvov8ugy7llpiq0xCMbfE0kzarkvEAe7LY39i7WMp4 gxcbjua65gdEDGVt5m4P4EIPunIka9YTu3xelZftpUaGE89YpGUmsXso0Fz/2jKg0A+O NkbA== X-Gm-Message-State: AO0yUKXsKrAMBnxUgMyLrAgDHsSOUXSYTN6XQ76/tPMSjAENTGJkuUm/ 5ipHVO6ZX83QsXbzzDGVL8Q= X-Google-Smtp-Source: AK7set/t/0K5QEwIP/T3c/ZbbeXNoZLsXoMg7aLC7Q1QAzA596qEZUK+p7wXS95ZdD6UPNM9vPwUlA== X-Received: by 2002:a2e:700e:0:b0:283:4310:da75 with SMTP id l14-20020a2e700e000000b002834310da75mr7315085ljc.39.1677419115522; Sun, 26 Feb 2023 05:45:15 -0800 (PST) Received: from osv.localdomain ([89.175.180.246]) by smtp.gmail.com with ESMTPSA id v11-20020a2ea44b000000b002935632b3f8sm416208ljn.14.2023.02.26.05.45.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 26 Feb 2023 05:45:14 -0800 (PST) From: Sergey Organov To: Gerz Burak LCPF-CH Cc: "linux-serial@vger.kernel.org" , "gregkh@linuxfoundation.org" , Sascha Hauer , "kernel@pengutronix.de" , "linux-imx@nxp.com" , Manuel Traut , Traut Manuel LCPF-CH Subject: Re: UART RX losing bytes References: Date: Sun, 26 Feb 2023 16:45:13 +0300 In-Reply-To: (Gerz Burak's message of "Sun, 26 Feb 2023 10:47:35 +0000") Message-ID: <87h6v8levq.fsf@osv.gnss.ru> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-serial@vger.kernel.org Hello, It reminds me about this: https://marc.info/?l=linux-serial&m=166479501704202&w=2 HTH, -- Sergey Gerz Burak LCPF-CH writes: > Hello, > > v6.1.14 on a Phytec phyBoard Segin i.MX 6ULL based board [0] is losing bytes on UART RX. > imx_v6_v7_defconfig was used. > > Minimalistic test to reproduce the issue: > > 1) Connect imx6ull UART with another machine > 2) imx6ull$ stty -F /dev/ttymxc0 115200 raw; cat /dev/ttymcx0 > 3) othermachine$ stty -F /dev/USB0 115200 raw; > echo "1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$%-.,()/&" > /dev/ttyUSB0 > > Expected result: > imx6ull: 1234567890abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$%-.,()/& > > Seen result (Many times, not always): > imx6ull: 1234567890abcdefghijklmnopqrstuvABCDEFGHIJKLMNOPQRSTUVWXYZ$%-.,()/& > or > imx6ull: 1234567890abcdefghijklmnopqrstuvBCDEFGHIJKLMNOPQRSTUVWXYZ$%-.,()/& > or > ... > > Setting scaling_governor to performance seems to be a workaround for this problem - but: > We are normally using the PREMPT_RT patch [1], and with this workaround bytes will still be lost > > Any hints how to track this down further? > > [0] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/arch/arm/boot/dts/imx6ull-phytec-segin-ff-rdk-nand.dts?h=v6.1.14 > [1] https://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git/tag/?h=v6.1.12-rt7