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=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 AC29CC433E1 for ; Wed, 17 Jun 2020 09:30:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8718C20739 for ; Wed, 17 Jun 2020 09:30:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726480AbgFQJau (ORCPT ); Wed, 17 Jun 2020 05:30:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41014 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725554AbgFQJau (ORCPT ); Wed, 17 Jun 2020 05:30:50 -0400 Received: from Galois.linutronix.de (Galois.linutronix.de [IPv6:2a0a:51c0:0:12e:550::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0E2EEC061573; Wed, 17 Jun 2020 02:30:50 -0700 (PDT) Received: from p5de0bf0b.dip0.t-ipconnect.de ([93.224.191.11] helo=nanos.tec.linutronix.de) by Galois.linutronix.de with esmtpsa (TLS1.2:DHE_RSA_AES_256_CBC_SHA256:256) (Exim 4.80) (envelope-from ) id 1jlUP8-0005no-6P; Wed, 17 Jun 2020 11:30:46 +0200 Received: by nanos.tec.linutronix.de (Postfix, from userid 1000) id 7FB37101548; Wed, 17 Jun 2020 11:30:44 +0200 (CEST) From: Thomas Gleixner To: Mark Brown , Krzysztof Kozlowski Cc: Vladimir Oltean , linux-spi@vger.kernel.org, "linux-kernel\@vger.kernel.org" , Marc Kleine-Budde , Wolfram Sang , kernel@pengutronix.de Subject: Re: [PATCH v2 3/3] genirq: Do not test disabled IRQs with DEBUG_SHIRQ In-Reply-To: <20200616103956.GL4447@sirena.org.uk> References: <1592208439-17594-1-git-send-email-krzk@kernel.org> <1592208439-17594-3-git-send-email-krzk@kernel.org> <20200615120844.GL4447@sirena.org.uk> <20200616103956.GL4447@sirena.org.uk> Date: Wed, 17 Jun 2020 11:30:44 +0200 Message-ID: <87mu52ca4b.fsf@nanos.tec.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Mark Brown writes: > On Tue, Jun 16, 2020 at 12:11:17PM +0200, Krzysztof Kozlowski wrote: >> On Mon, Jun 15, 2020 at 01:08:44PM +0100, Mark Brown wrote: >> > On Mon, Jun 15, 2020 at 10:07:19AM +0200, Krzysztof Kozlowski wrote: >> > > Testing events during freeing of disabled shared interrupts >> > > (CONFIG_DEBUG_SHIRQ) leads to false positives. The driver disabled >> > > interrupts on purpose to be sure that they will not fire during device >> > > removal. > >> > Surely the whole issue with shared IRQs that's being tested for here is >> > that when the interrupt is shared some other device connected to the >> > same interrupt line may trigger an interrupt regardless of what's going >> > on with this device? > >> Yes. However if that device disabled the interrupt, it should not be >> fired for other users. In such case the testing does not point to a >> real issue. > > To be honest I'd say that if you're disabling a shared interrupt that's > a bit of an issue regardless of anything else that's going on, it'll > disrupt other devices connected to it. Correct. Shared interrupts are broken by design and I really can't understand why hardware people still insist on them. Thanks, tglx