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=-4.0 required=3.0 tests=BAYES_00,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 C8E91C433DB for ; Mon, 22 Feb 2021 12:56:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8076A64E76 for ; Mon, 22 Feb 2021 12:56:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230520AbhBVM4m (ORCPT ); Mon, 22 Feb 2021 07:56:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:49206 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231255AbhBVMXs (ORCPT ); Mon, 22 Feb 2021 07:23:48 -0500 Received: from disco-boy.misterjones.org (disco-boy.misterjones.org [51.254.78.96]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 85ED564E61; Mon, 22 Feb 2021 12:23:07 +0000 (UTC) Received: from 78.163-31-62.static.virginmediabusiness.co.uk ([62.31.163.78] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94) (envelope-from ) id 1lEAEz-00FJdN-6a; Mon, 22 Feb 2021 12:23:05 +0000 Date: Mon, 22 Feb 2021 12:23:04 +0000 Message-ID: <87ft1o1ec7.wl-maz@kernel.org> From: Marc Zyngier To: Mark Rutland Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, james.morse@arm.com, marcan@marcan.st, tglx@linutronix.de, will@kernel.org Subject: Re: [PATCH 5/8] arm64: irq: add a default handle_irq panic function In-Reply-To: <20210222120614.GC70951@C02TD0UTHF1T.local> References: <20210219113904.41736-1-mark.rutland@arm.com> <20210219113904.41736-6-mark.rutland@arm.com> <20210222095913.GA70951@C02TD0UTHF1T.local> <1d2c27d72b9b2cbdb83d25165a20559a@kernel.org> <20210222112544.GB70951@C02TD0UTHF1T.local> <2e6a9659eabcccb355318ff7214c8d1f@kernel.org> <20210222120614.GC70951@C02TD0UTHF1T.local> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 62.31.163.78 X-SA-Exim-Rcpt-To: mark.rutland@arm.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, james.morse@arm.com, marcan@marcan.st, tglx@linutronix.de, will@kernel.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 22 Feb 2021 12:06:14 +0000, Mark Rutland wrote: > > On Mon, Feb 22, 2021 at 11:43:13AM +0000, Marc Zyngier wrote: [...] > > As I said, it's not a big deal. I doubt that we'll see default_handle_irq() > > exploding in practice. But the real nit here is the difference of treatment > > between IRQ and FIQ. *IF* we ever get a system that only signals its > > interrupt as FIQ (and I don't see why we'd forbid that), then we would > > That's a fair point. > > For consistency, we could remove the init_IRQ() panic() and instead log > the registered handlers, e.g. > > | pr_info("Root IRQ handler is %ps\n", handle_arch_irq); > | pr_info("Root FIQ handler is %ps\n", handle_arch_fiq); > > ... or do that inside the set_handle_{irq,fiq}() functions. That way the > messages (or absence thereof) would be sufficient to diagnose the lack > of a root IRQ/FIQ handler when IRQ/FIQ happens to be quiescent. > > Does that sound any better? Yup, I quite like the second variant (using set_handle_{irq,fiq}()). Thanks, M. -- Without deviation from the norm, progress is not possible.