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=-0.8 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,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 D107EC433E0 for ; Wed, 8 Jul 2020 08:07:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A942420775 for ; Wed, 8 Jul 2020 08:07:16 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="TRDJKmAp" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726741AbgGHIHP (ORCPT ); Wed, 8 Jul 2020 04:07:15 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46966 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726285AbgGHIHP (ORCPT ); Wed, 8 Jul 2020 04:07:15 -0400 Received: from mail-pj1-x1042.google.com (mail-pj1-x1042.google.com [IPv6:2607:f8b0:4864:20::1042]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D51FBC08C5DC for ; Wed, 8 Jul 2020 01:07:14 -0700 (PDT) Received: by mail-pj1-x1042.google.com with SMTP id gc15so1862886pjb.0 for ; Wed, 08 Jul 2020 01:07:14 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:date:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=zgzFBfd1L8gIswoLsa9e4bScB/4Us/z7PKgKE1kxKk0=; b=TRDJKmApQQAgV1F8yAcsr7qqPMqF9bluQIsXh5qPLmghCHbJ8NP3OAnDdlEjEIdfrG PuchHLjwb6SA3djTfP0AbHhk8YSQvR/V8xt9XIDmVqnhChRLS6aFQChmOIxvLioQlZkU mQ6L0FHn9yT4CciTyXmcQ/VfHL+2dM7Ek0smfDoOlMc6mLQzum00ZRqPUrdtpeBPHB8H qDpIgtAbr/EDZV6f4fZlgJ+hCZlGud51Jc2M59ypZhlrMjFa66XYFHe73lOBHFFjSFrV VrDGE4rRbb9nvIQWEg5POM0dDCecD8sX7T9zKGQhZsnc5xfqiEZV4plcUnA8Zt4od6q6 1+aA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:date:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=zgzFBfd1L8gIswoLsa9e4bScB/4Us/z7PKgKE1kxKk0=; b=Szwukb/MNr1pDGwur+K22VqoS98Xkyd8IbBGQ2M3TXQkgtYWGtOgyEC/1Tqs0XvQoL GPLmd26hD2DHgBvMLnMpsl4vG0/YqiEuPa0gtzegsdUur0vJ049jCbATCu6fMXSX4W0G LAvdMEt7CU0no925+V1IfNI30iLqNpASxfIftws1enTt6KUr+EXZVd7z3hnYMiwD2wok tmVoSWxa1zxcKBi1arFhxqu0V10sOwu1ZC1Ahbc595URkg72HGJEAi3cQOvNeal9aOT6 YdYKLr0h8P4tJ9FiYCoDclsrpYbpwsKidgnPh4QIxzrnlkJZtlivI12iJgKOyUJPYfbT 5GhQ== X-Gm-Message-State: AOAM532vmM9aVUD6T96NvaaF9sNMY5d5mwGZAb/XpZd7K3voUrbGfCzK EuorbOQLtrbMrNjvGNdnTtRaZRF/ X-Google-Smtp-Source: ABdhPJxILI9kIQVi/IzMOCbDxxFrikiBeyiop3NvXUYPgNvMjePeIEmdB8WnFfWYdLpZIagendcrTQ== X-Received: by 2002:a17:90a:3525:: with SMTP id q34mr6911330pjb.192.1594195634298; Wed, 08 Jul 2020 01:07:14 -0700 (PDT) Received: from localhost ([2409:10:2e40:5100:6e29:95ff:fe2d:8f34]) by smtp.gmail.com with ESMTPSA id c132sm23925453pfb.112.2020.07.08.01.07.13 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 08 Jul 2020 01:07:13 -0700 (PDT) From: Sergey Senozhatsky X-Google-Original-From: Sergey Senozhatsky Date: Wed, 8 Jul 2020 17:07:12 +0900 To: Kurt Kanzenbach Cc: Sergey Senozhatsky , Andy Shevchenko , Tony Lindgren , Petr Mladek , Raul Rangel , Sergey Senozhatsky , linux-kernel , Greg Kroah-Hartman , Andy Shevchenko , "S, Shirish" , Peter Zijlstra , John Ogness , Steven Rostedt Subject: Re: UART/TTY console deadlock Message-ID: <20200708080712.GC571@jagdpanzerIV.localdomain> References: <20200630122239.GD6173@alley> <20200630130534.GB145027@jagdpanzerIV.localdomain> <20200630180255.GD37466@atomide.com> <20200702051213.GB3450@jagdpanzerIV.localdomain> <20200702160514.GK37466@atomide.com> <20200703103241.GB182102@jagdpanzerIV.localdomain> <877dvg6ft6.fsf@kurt> <20200706144314.GB1485@jagdpanzerIV.localdomain> <87o8oqa1zy.fsf@kurt> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87o8oqa1zy.fsf@kurt> Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On (20/07/08 09:40), Kurt Kanzenbach wrote: > I'm not sure how this patch will help with the situation. Because at the > point of that THRE test the irq handler isn't registered. It's > registered a few lines below (up->ops->setup_irq()) meaning the irq line > has to be disabled if shared. Otherwise the kernel might detect a > spurious irq and disables it. That's at least my understanding of the > problem (see commit message from 54e53b2e8081 ("tty: serial: 8250: pass > IRQ shared flag to UART ports")). So the only remaining approach then is to move disable_irq_nosync()/enable_irq() out of port->lock scope. -ss