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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 61911C79F80 for ; Fri, 4 Sep 2026 07:39:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Type:MIME-Version: References:In-Reply-To:Subject:Cc:To:From:Message-ID:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yLqpYDkV7tEDFi1t5AdTF7wzKnvFLphitDHQQVK47uM=; b=Mpa1YVWYcBKLO54vljbOd7wxRn ZHoXoQuJoCxMQuVuz7HDG0Bssg0Lb8it9bo30J2WIRZIAiyvSocIYOCvLeYXDqDHLr0wpmWxSafTg 15MAfpW02QLwusd8QkQblKtXs3G162V9wsz1t2smLpMJFfn/mk6z9Y2fs2EK74ujO+a1oLFbUWs71 jt4FevB7Qomf0gY1quLycqv3VtU5nWkQfRy5tFUM9k57qi8Z7osLZwmV0Fs9PUdX2PUvLxhiiBQvc GMBdbbOoDO50+R0DWYXVQv7RN9WRnRJXBb91m01W9QiwKhXiQYBNXX/in/OR1L8fhYNsSVMqDhr+0 CXtRVgVA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2OWd-00000001FkU-2K4M; Fri, 04 Sep 2026 07:39:51 +0000 Received: from sea.source.kernel.org ([172.234.252.31]) by bombadil.infradead.org with esmtps (Exim 4.99.1 #2 (Red Hat Linux)) id 1x2OWc-00000001FkL-1yh2 for linux-arm-kernel@lists.infradead.org; Fri, 04 Sep 2026 07:39:50 +0000 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id CDC8541A3B; Fri, 4 Sep 2026 07:39:49 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id B021B1F00A3D; Fri, 4 Sep 2026 07:39:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788507589; bh=yLqpYDkV7tEDFi1t5AdTF7wzKnvFLphitDHQQVK47uM=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=TZ0Bj+HJQULHZWAGNu23D46FAX/zQkJrKj/98YwyCCpKhkDYmmyHpePGN9s/3Nu+q 21N3Oftz9rSmrp1eq/G1R/yX30BDhOj0ClfI50XhbxFejDWXxue4NKXbIVW/XgCPvO 0YsNToy6lKfsOWZrF1654/buRtk0fWq3JYps7oWf+Jkmnc64WJ90H4OB77gRbr46Gx jL4bPTxaxkgJjrusk6EWnLMEMh0yRaQZ0Z0SzbAOV3xAD8w3qyw3phsxOzLgIPVWcX rT2J7HnsCA8q7zV0HbIWawOVThhV7L9mE5lJH9hOaFUzg7gm634QzmE1k4Cd9rVQO9 0pRD8x+54iLxA== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1x2OWZ-00000004hLu-20xL; Fri, 04 Sep 2026 07:39:47 +0000 Date: Fri, 04 Sep 2026 08:39:47 +0100 Message-ID: <86mrtx4g8s.wl-maz@kernel.org> From: Marc Zyngier To: Jiangshan Yi Cc: lpieralisi@kernel.org, tglx@kernel.org, radu@rendec.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, 13667453960@163.com Subject: Re: [PATCH v2] irqchip/gic-v5: Install root IRQ handler last in gicv5_init_common() In-Reply-To: <20260903104014.587068-1-yijiangshan@kylinos.cn> References: <20260903104014.587068-1-yijiangshan@kylinos.cn> 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/30.1 (aarch64-unknown-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: 185.219.108.64 X-SA-Exim-Rcpt-To: yijiangshan@kylinos.cn, lpieralisi@kernel.org, tglx@kernel.org, radu@rendec.net, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, 13667453960@163.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Thu, 03 Sep 2026 11:40:14 +0100, Jiangshan Yi wrote: > > set_handle_irq() cannot be undone: once a handler is installed, any > further call returns -EBUSY, so the set_handle_irq(NULL) in the error > path has never worked. Drop it, and install the root handler only > after gicv5_irs_enable() has succeeded. > > set_handle_irq() only fails if another root handler is already > installed, which cannot happen on a GICv5 system. Should it ever > fail, the system is unusable: panic instead of unwinding. Note that the system is dead either way, as it isn't like someone is going to provide a replacement interrupt controller when GICv5 fails. So any error in this function is pretty fatal for the whole system. That said, this is still a reasonable cleanup. > > Link: https://lore.kernel.org/r/87fqzrmywu.wl-maz@kernel.org > Signed-off-by: Jiangshan Yi Reviewed-by: Marc Zyngier M. -- Without deviation from the norm, progress is not possible.