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 2D355C433F5 for ; Sat, 21 May 2022 19:41:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231462AbiEUTl5 (ORCPT ); Sat, 21 May 2022 15:41:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60972 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230127AbiEUTl4 (ORCPT ); Sat, 21 May 2022 15:41:56 -0400 Received: from mout.kundenserver.de (mout.kundenserver.de [217.72.192.74]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1A9C83E5D3; Sat, 21 May 2022 12:41:51 -0700 (PDT) Received: from mail-yw1-f171.google.com ([209.85.128.171]) by mrelayeu.kundenserver.de (mreue109 [213.165.67.113]) with ESMTPSA (Nemesis) id 1MatZt-1nHWfW1MXz-00cRs9; Sat, 21 May 2022 21:41:49 +0200 Received: by mail-yw1-f171.google.com with SMTP id 00721157ae682-2ef5380669cso115100417b3.9; Sat, 21 May 2022 12:41:49 -0700 (PDT) X-Gm-Message-State: AOAM530ykxv1M15oI+egNT+tLlRgaZBeu/E9w5DLFbFm0Ty9GhkZJey5 PADyDQkVR+3zi0cRtAphxEDBm9gg1AOB7RBgPYs= X-Google-Smtp-Source: ABdhPJwrgsMN7Ijgz9GAFGljoJxtQGD9GNwQNTcNuNXHJ2ZAL6jmu8b+7bNBJ5lr3aVVb/VrAwQ23AcpRu82ecv6gFg= X-Received: by 2002:a0d:fc83:0:b0:2e5:b0f4:c125 with SMTP id m125-20020a0dfc83000000b002e5b0f4c125mr16588097ywf.347.1653162107872; Sat, 21 May 2022 12:41:47 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Sat, 21 May 2022 21:41:30 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: am335x: 5.18.x: system stalling To: Yegor Yefremov Cc: Arnd Bergmann , Tony Lindgren , Ard Biesheuvel , Linux-OMAP , linux-clk , Stephen Boyd , Linux ARM Content-Type: text/plain; charset="UTF-8" X-Provags-ID: V03:K1:VY39/sLenORkliBZhWfb1XSBeuUrcAgHekxdbPepEkMFg03GT7W FQexP6oyNRDDaoHEoippoRiGKAYh7lbj230uZKhsE02EByGC7fUKR5MGFVAQZSn6UAc85p+ Kin+lmZxeGoi73/au40UptoGTkgNedht+ooXFp/Qk13q4kcrC3eEUNkJQ5vB/hcwU/ylfxx Kd1pl4+oXYgXPzKwNe6pw== X-UI-Out-Filterresults: notjunk:1;V03:K0:0gSwTFOLAm8=:eV7mRooO51PZX5gBs/v/0D 3auoSn3HHl+Uoc69FfdIq28I8YKETDd9C2vibFaERd5B8Ud9fzY6wzciGqfzqdDlNQUjqkkMX qgXSfyAFhzgzp4cTKcBF4XgE6BylXwX7Xtc0qi6Uw8nU6j2v6gQ1sJVdex3gm+X0Mbc8LhNRd uxN6M/eZfogppYlny1Zv5AQrXyYDkRQErX53rZDgodbKeFHkX6VpYQf31b79i5ESJZFr7Or4M IxMkIDKuVaTLEclE9aJ4qZAAhFGPDWu6Rk2OD7LJBUVb7vEg8NUA1p+P4W9B87qc6/25Fvbrd 7mUEAYNig423WCx1ZV4Skjz8/M/UTwh5XVHuQKUu0FK/5c2W44MwqLOzYXSru+g1i9cn8nmaK VkrAh6IYJnYfIsAbYbUDboFHPQclOgLHOiurZs81sxK6K/hDWfB/lbt621qpA8PEX8CeOSbhz ihrr56WInxxWA81zgx9XzYmQ9DPTJlul/Lrjs+Nb2RHWDkluLYNWnYsfSfVp1kOSOzAlJleiU yzy95PecbIMR1aDRoFLwRucJM+auUev5sasMdKTcia3nLTtLRjC+/z9yBnlzRI1m5IL7v2aUA HkuVo3s3/8yRNl7aLdHdRQdjbbx1nWEx4qPjRYaB3u9R42KwvQ24ldiu+O2HJMQnoK6ujK/6a Hn99z0j8ogJbrtXdvJPDDT+3PZYHdcyXqc/IWZf2+w0WpaXlhIYlhJy4YD7ig5zbRnfm4vbIq gvFgJWXhx4lHNhIZAlUbqop+5l/S0obKuFHUEg== Precedence: bulk List-ID: X-Mailing-List: linux-clk@vger.kernel.org On Thu, May 19, 2022 at 5:52 PM Yegor Yefremov wrote: > On Thu, May 12, 2022 at 12:20 PM Yegor Yefremov > wrote: > > On Thu, May 12, 2022 at 10:43 AM Arnd Bergmann wrote: > > > > > > On Thu, May 12, 2022 at 7:41 AM Tony Lindgren wrote: > > > > * Yegor Yefremov [220511 14:16]: > > > > > On Thu, May 5, 2022 at 7:08 AM Tony Lindgren wrote: > > > > > > * Yegor Yefremov [220504 10:35]: > > > > > > > Hi Tony, all, > > > > > > > > > > > > > > since kernel 5.18.x (5.17.x doesn't show this behavior), the system > > > > > > > stalls as soon as I invoke the following commands (initializing > > > > > > > USB-to-CAN converter): > > > > > > > > > > > > > > slcand -o -s8 -t hw -S 3000000 /dev/ttyUSB0 > > > > > > > ip link set slcan0 up > > > > > > Oh, I missed this part at first and only looked at the backtrace. > > > Which CAN driver > > > are you using? It's likely a problem in the kernel driver. > > > > I am using the slcan driver [1]. Ok, so this is just a serial port based driver, which means the follow-up question is what you use for your uart. Is this one of the USB-serial ones or an on-chip uart? Which driver? > > > CONFIG_DMA_API_DEBUG is still likely to pinpoint the bug, but I might also > > > just see it by looking at the right source file. > > > > I'll try to get more debug info with CONFIG_DMA_API_DEBUG. > > DMA_API_DEBUG showed nothing new. But disabling the CPUfreq driver > "solved" the problem. I have tried different governors and got these > two groups: > > ondemand, schedutil - cause the problem > conservative, powersave, performance and userspace - don't cause the problem > > So far, I have only seen the same debug output that I've initially > sent and in most cases, the system stalls without the output. Ok, so that sounds like it happens when you change the frequency. I assume this means you are using drivers/cpufreq/omap-cpufreq.c? When using the usersapce governor, do you see problems when you manually change the frequency from sysfs? Arnd 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 A6C8CC433EF for ; Sat, 21 May 2022 19:43:21 +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-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:Cc:To:Subject:Message-ID:Date:From: In-Reply-To:References:MIME-Version:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=1VJEhx0EDgU+tRnvE+O70090ucsjrgE8aI2O0/7+JKs=; b=nRahdaWHo1AvCo 1H7dyeF+LZU9eL+CvXbo18BuT/zoj/awVai06vCE3ivG4LXyeNOp4O+mm2XcbZQ82g/tk9pDr9+oe Qm7EYTc9i/Lt6Baptsk1hEaoER9bNgDv9oWWHhVRHyf48vTkqiKW3br+NysQ2Atq+0IJYRc64blI2 jfSnP4lluKdCFxM7KV1nOprRgWhXKvawETDlpvytAbsukl2edPcZwYi41EkbfWJla41OotzGA1Hk8 GLVm+Xoh8rWoYlIeZifbjLkQdHguBvSzQdF6yjCMpZolrQDyt91dnOeMZUmVfiiUkhLTqwOVCnr+X 6p/TkZitNh/dyjUthCxQ==; 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Sat, 21 May 2022 12:41:47 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Arnd Bergmann Date: Sat, 21 May 2022 21:41:30 +0200 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: am335x: 5.18.x: system stalling To: Yegor Yefremov Cc: Arnd Bergmann , Tony Lindgren , Ard Biesheuvel , Linux-OMAP , linux-clk , Stephen Boyd , Linux ARM X-Provags-ID: V03:K1:/nZf5fA/Aa3Jnrc4TP5d00TR3JZ06z3GCzJ1vo7Zz0ZuvrN8dt/ GgNcFn36EYxMgAz0eguGnJIOehY6IXSz3uKAOikLwXukkDzWy9nCBCuQwwTs3msHBB5U0VJ R48iUbVEYMTDnwsddyTDQ365LQp05CXTkfcsdjGlkYTBv664Mqf5qTRlFyQ4oCElRNEqYq7 7hS6GWkWQau3mWsRgompg== X-UI-Out-Filterresults: notjunk:1;V03:K0:hR+fyTH09TQ=:2VRPvguH0pwASNNZnK/LG5 RVamkJ8v/Wb9U9FsUFrwqYmeWJqrhfbeaJFNDneF6ZQ32SNymWeqoopjhmxmozJViwYXF5et1 9E2D3ueXYdLapVpBhf36ZPVgXB3ddVwXSz976QcaYi2sWpk+TPmXiV/85BuYdwDbsEvrkJGnP W86Q+irUzQeAIykxNLOE2lHh2RuN93MS90JhBwFAfB2ht16CZLAmUa0cuY3R4/85v/TzOHQip s5cukkKpXOq+aYgTSMRsYUq/wxJASQHagj4DwBMjd2hcpN1+FhjBwtzh6JThogHG45agpN+7t 9GYGxFvr+OA6koAxpAIcFVO8LYfi5g/iWTAbrLe6Jauzwl7YE180y7P1AnMJigA41SU8dmIBq +LUzzWaHNh/xKeZNPzlL2FO4ykNQRsulPapKI7z47orOVoi5JG219kHe057X5whPkM/M3WRzP A5VmtGO8m1oKuRLPVJP2ViQrdDLEsRlhpQ5n8uMLgi52Tru3eTZvXX0tg1yargUVbSPPHXKAn Pu65xQzTfGkoGc+onUmIE9LiAWjPfi/EF0cnjIUY1mN5SwRz6Cg2BIOqXhl5Vu+BuyOv6RrPS DmSAamN/pk09Gzx4J9SEVz4putINWzW0MROfv2YCkiCSW0ojDkwnpSjTgvBziW/U5wnzn93V0 s0vPa0d+l9TIJPSJ8XJIe+TatEHFRHE+5eQyAmH0it2ILKEg00DmmgPXnRv3D11ldA/OjWUiB mqANmrbLmWd0mYq6+30wpOSStulH/ys1Sviymw== X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220521_124155_014254_66E0A903 X-CRM114-Status: GOOD ( 26.90 ) 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-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, May 19, 2022 at 5:52 PM Yegor Yefremov wrote: > On Thu, May 12, 2022 at 12:20 PM Yegor Yefremov > wrote: > > On Thu, May 12, 2022 at 10:43 AM Arnd Bergmann wrote: > > > > > > On Thu, May 12, 2022 at 7:41 AM Tony Lindgren wrote: > > > > * Yegor Yefremov [220511 14:16]: > > > > > On Thu, May 5, 2022 at 7:08 AM Tony Lindgren wrote: > > > > > > * Yegor Yefremov [220504 10:35]: > > > > > > > Hi Tony, all, > > > > > > > > > > > > > > since kernel 5.18.x (5.17.x doesn't show this behavior), the system > > > > > > > stalls as soon as I invoke the following commands (initializing > > > > > > > USB-to-CAN converter): > > > > > > > > > > > > > > slcand -o -s8 -t hw -S 3000000 /dev/ttyUSB0 > > > > > > > ip link set slcan0 up > > > > > > Oh, I missed this part at first and only looked at the backtrace. > > > Which CAN driver > > > are you using? It's likely a problem in the kernel driver. > > > > I am using the slcan driver [1]. Ok, so this is just a serial port based driver, which means the follow-up question is what you use for your uart. Is this one of the USB-serial ones or an on-chip uart? Which driver? > > > CONFIG_DMA_API_DEBUG is still likely to pinpoint the bug, but I might also > > > just see it by looking at the right source file. > > > > I'll try to get more debug info with CONFIG_DMA_API_DEBUG. > > DMA_API_DEBUG showed nothing new. But disabling the CPUfreq driver > "solved" the problem. I have tried different governors and got these > two groups: > > ondemand, schedutil - cause the problem > conservative, powersave, performance and userspace - don't cause the problem > > So far, I have only seen the same debug output that I've initially > sent and in most cases, the system stalls without the output. Ok, so that sounds like it happens when you change the frequency. I assume this means you are using drivers/cpufreq/omap-cpufreq.c? When using the usersapce governor, do you see problems when you manually change the frequency from sysfs? Arnd _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel