From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Sat, 02 Apr 2016 14:19:16 +0200 (CEST) Received: from mail-lb0-f194.google.com ([209.85.217.194]:35755 "EHLO mail-lb0-f194.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S27014287AbcDBMTN4lUcR (ORCPT ); Sat, 2 Apr 2016 14:19:13 +0200 Received: by mail-lb0-f194.google.com with SMTP id gk8so10522189lbc.2; Sat, 02 Apr 2016 05:19:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=subject:to:references:cc:from:message-id:date:user-agent :mime-version:in-reply-to:content-transfer-encoding; bh=ZEEJWKgqHSQdaqOLu56vOqKen0y1SgofRSsrJJ6WHNo=; b=IjwAMF9W9oMZdfG9StYPK0lkO1d4Eiq3kRUA+yEez6oe/SGmqUDPHe88yIP7F7c9Wf 8eR7CNTlJS/XLDp3PLV/UdNmDaJIAh6IrSTlvB6hHcp0KDCZOTasLYeYDyz1ARp/iIdt 70bNufM3pofpwV9/nUAHb8m2hq64Ivy1lFGk65DGjf7hPeuf6AYPY7uvxm2vTVo3TUrZ /6MuRAr5sUYvnToCprze4lS9fN28zU3/Xv6iXWQY1FY1sopFO43S68+E/0I/NtZwAe04 iA4h/fMToZ+RnjulUaW8eZ03EV5KgV7CkPon2S+SJaJ3PSBd/LtZ5b4A9Foz/hcmUmnf IcQg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:subject:to:references:cc:from:message-id:date :user-agent:mime-version:in-reply-to:content-transfer-encoding; bh=ZEEJWKgqHSQdaqOLu56vOqKen0y1SgofRSsrJJ6WHNo=; b=as+68859q1G4eN+XBPp2gaacAUStXn1Flfa4tUrwDcsC75osqHqySrQnzrxWDfqY3c v/x3vDmB23SJR7Q8WLRqhKVOPHqJGeqsLiudK5AgKPYNuxgl0Icz46/q9WSK5w9Wr4+y xhYRHqd7iV4upLcO93OTNpDLYQIunUU+tue4r1O7zZ/+X1zAJOpKcVYEa4VDigJKEd6d MZngIF41j939BaMf98X39H1E7+ma1EQJzzGPhYA/ZI6PFP4qqMZEtjhlfsWuUvp6+2O+ KCgxnc+pAKDkyM2gDFJp+yJrV2a5OwqgBP9C/oZS2IocyrZROujyCx/JSg8J5O3d1/VB E5ag== X-Gm-Message-State: AD7BkJLdKo76h/jSiahFWbHnkIkfcZMktTehURIp2q2VlEBP0Y2aUUb53pQRGJoQ4MtcrQ== X-Received: by 10.28.24.80 with SMTP id 77mr3205357wmy.16.1459599548516; Sat, 02 Apr 2016 05:19:08 -0700 (PDT) Received: from Qaiss-MacBook-Pro.local (92.40.248.138.threembb.co.uk. [92.40.248.138]) by smtp.gmail.com with ESMTPSA id w202sm2424491wmw.18.2016.04.02.05.19.07 (version=TLSv1/SSLv3 cipher=OTHER); Sat, 02 Apr 2016 05:19:07 -0700 (PDT) Subject: Re: [PATCH] MIPS: Fix broken malta qemu To: Paul Burton , ralf@linux-mips.org References: <1458248889-24663-1-git-send-email-qsyousef@gmail.com> <20160401124852.GA5145@NP-P-BURTON> Cc: Guenter Roeck , Thomas Gleixner , linux-mips@linux-mips.org, linux-kernel@vger.kernel.org From: Qais Yousef Message-ID: <56FFB8B7.8050607@gmail.com> Date: Sat, 2 Apr 2016 13:19:03 +0100 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:38.0) Gecko/20100101 Thunderbird/38.6.0 MIME-Version: 1.0 In-Reply-To: <20160401124852.GA5145@NP-P-BURTON> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 52836 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: qsyousef@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips Hi Paul, On 01/04/2016 13:48, Paul Burton wrote: > On Thu, Mar 17, 2016 at 09:08:09PM +0000, Qais Yousef wrote: >> Malta defconfig compiles with GIC on. Hence when compiling for SMP it causes the >> new IPI code to be activated. But on qemu malta there's no GIC causing a >> BUG_ON(!ipidomain) to be hit in mips_smp_ipi_init(). >> >> Since in that configuration one can only run a single core SMP (!), skip IPI >> initialisation if we detect that this is the case. It is a sensible behaviour >> to introduce and should keep such possible configuration to run rather than die >> hard unnecessarily. > Hi Qais/Ralf, > > This patch is insufficient I'm afraid. It's entirely possible to use SMP > with multiple VPEs in a single core on Malta boards that don't have a > GIC - we have code handling IPIs in that case guarded by #ifdef > CONFIG_MIPS_MT_SMP in arch/mips/mti-malta/malta-int.c. I think the > BUG_ON needs to be removed entirely, unless that single-core multi-VPE > IPI code is also converted to use an IPI irqdomain. > I was under the impression that SMP is only supported under GIC and older forms of SMP are deprecated. I think the problem you're describing is different to the one this is trying to fix. The right fix for your issue is to make CONFIG_GENERIC_IRQ_IPI selected when CONFIG_MIPS_GIC && !CONFIG_MIPS_MT_SMP. Would it be easy for you to create such a patch and test it? Thanks, Qais