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=-2.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_SANE_1 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 E6871C433E0 for ; Thu, 4 Jun 2020 11:59:26 +0000 (UTC) Received: from lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id A5AA920738 for ; Thu, 4 Jun 2020 11:59:26 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=mvista-com.20150623.gappssmtp.com header.i=@mvista-com.20150623.gappssmtp.com header.b="KPoKu+Qj" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A5AA920738 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mvista.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jgoWh-0000GR-G9; Thu, 04 Jun 2020 11:59:15 +0000 Received: from us1-rack-iad1.inumbo.com ([172.99.69.81]) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1jgoWg-0000GE-0x for xen-devel@lists.xenproject.org; Thu, 04 Jun 2020 11:59:14 +0000 X-Inumbo-ID: ccdd0e1e-a65a-11ea-9947-bc764e2007e4 Received: from mail-oi1-x243.google.com (unknown [2607:f8b0:4864:20::243]) by us1-rack-iad1.inumbo.com (Halon) with ESMTPS id ccdd0e1e-a65a-11ea-9947-bc764e2007e4; Thu, 04 Jun 2020 11:59:10 +0000 (UTC) Received: by mail-oi1-x243.google.com with SMTP id j189so4799463oih.10 for ; Thu, 04 Jun 2020 04:59:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=mvista-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:reply-to:references:mime-version :content-disposition:in-reply-to:user-agent; bh=MP+MSIIv1u5nMjP12qFOOqmxhDupPPSuAsiS0Q7kPh8=; b=KPoKu+QjsSf/3CVTmbiW61qyvxa7L+kfeCuQwJ7CXjFHy6Jrb8LGGHLeqYrfju3vBG L76jKx9fpWPIj8bZnoWTlmwf6zKlo+I8hOYjD+KpPevMKiwD3lTqoTpJE/QGiHqvEQSv Lc27GYfLqWo3oqXL7fFIB5xn8NQVBddMcyDJ5/57eltI7wFCk2FJcf88HsGxeQjc97PK 9kCN0T2nwIIzSeVvhfHskZ1REDJ/mYOSE0qJNHDjRWIWyyDxxcW1r0dMTW4jy98qkx5T Ss+BIHPRFQSH38zquhl2xOWJe/zj9S0zw+sCw/ptRGBBAvGV+WmAZwqnTP0lmIc+YmPI 6jSw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:reply-to :references:mime-version:content-disposition:in-reply-to:user-agent; bh=MP+MSIIv1u5nMjP12qFOOqmxhDupPPSuAsiS0Q7kPh8=; b=sl6RFw29NsZe67XLHtHdrMRYfMjdBDao0pWbE8g84FTCkMAeic1AeRaEU0desGvht1 3aSj/SBLark+kKZK7ioq+n3wO0/PB6wJzKJc9jk0tE/Qgy3j29RPm7JTk8FmRJwHrxoK 9lXv+LtBfWtGNsy5P7AVBMicM0Po6o7H9aFwKN4gIeTNXP/5/ugMwnshyyqOethYXmQ3 DyZgSqT+nl7kprdopl0+/Vq9wqvmE7RQtuTXC42OaO3Uy/fRbRFTeYXF/rJ8IVTxTM1Q Jea5aN2OJejVEKdz4cM3f9jPaUsboUTdAaPjuWoqmmthbqy9f/XfLUNrXHzBREGKE2Pw tFVg== X-Gm-Message-State: AOAM5301jAPkKnF64C1/lZ0gHNidLDq+6u4yF7v7VEZfJOWksturN5vv K5wX6kxtK1iSDYdBsxG46mK9eEj0IEo= X-Google-Smtp-Source: ABdhPJz69RfwEVipNTi6DzGS/HAU+oavhlaLxYHsKLyUUrMcde30wMQgCwHOLB4sDkS4PgZ/lk+1OQ== X-Received: by 2002:aca:d583:: with SMTP id m125mr2821909oig.138.1591271949814; Thu, 04 Jun 2020 04:59:09 -0700 (PDT) Received: from minyard.net ([2001:470:b8f6:1b:9d35:f7bd:647:6545]) by smtp.gmail.com with ESMTPSA id j2sm1059292otk.61.2020.06.04.04.59.08 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 04 Jun 2020 04:59:09 -0700 (PDT) Date: Thu, 4 Jun 2020 06:59:07 -0500 From: Corey Minyard To: Julien Grall Subject: Re: [PATCH] xen/rpi4: implement watchdog-based reset Message-ID: <20200604115907.GD2903@minyard.net> References: <20200603223156.12767-1-sstabellini@kernel.org> <20200604001552.GC2903@minyard.net> <50ad4bca-5eb8-8db0-0aae-dc7febfdb56a@xen.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <50ad4bca-5eb8-8db0-0aae-dc7febfdb56a@xen.org> User-Agent: Mutt/1.9.4 (2018-02-28) X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Reply-To: cminyard@mvista.com Cc: xen-devel@lists.xenproject.org, Stefano Stabellini , tamas@tklengyel.com, roman@zededa.com, Stefano Stabellini Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" On Thu, Jun 04, 2020 at 09:15:33AM +0100, Julien Grall wrote: > Hi, > > On 04/06/2020 01:15, Corey Minyard wrote: > > On Wed, Jun 03, 2020 at 03:31:56PM -0700, Stefano Stabellini wrote: > > > Touching the watchdog is required to be able to reboot the board. > > > > > > The implementation is based on > > > drivers/watchdog/bcm2835_wdt.c:__bcm2835_restart in Linux. > > > > Ah, I was looking at this just today, as it had been annoying me > > greatly. This works for me, so: > > > > Tested-by: Corey Minyard > > > > However, I was wondering if it might be better to handle this by failing > > the operation in xen and passing it back to dom0 to do. On the Pi you > > send a firmware message to reboot, and that seems like too much to do in > > Xen, but it would seem possible to send this back to dom0. > I don't think this is possible in the current setup. Xen will usually > restart the platform if Dom0 requested a clean reboot or crashed. So the > domain wouldn't be in state to service such call. Ok, I hadn't looked at Xen yet, I didn't know how much shutdown of dom0 happens on a reset. > > > Just a > > thought, as it might be a more general fix for other devices in the same > > situation. > > What are the devices you have in mind? Nothing in particular, but other systems might have the same issue. I guess you have ACPI implemented on x86 already. It just seemed that Linux already has to be able to do this, and passing the buck back there might be a more general solution. Thanks, -corey > > Cheers, > > -- > Julien Grall