From nobody Mon Feb 9 10:32:35 2026 Received: from mta-65-227.siemens.flowmailer.net (mta-65-227.siemens.flowmailer.net [185.136.65.227]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 976C721ADC1 for ; Fri, 7 Mar 2025 13:53:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.65.227 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741355618; cv=none; b=Rp5RsJw/kYRibCRJZ944Ex+LI22yistHqNyRkmP8nYTIHgIPg6nS1nI+vo31bWimFV1zcH02YyksAF+3bG92YHdtqEipgvPPzc1kxk31bTokC8mGpC1QyoJMAL8AV39knAtZM5Yrx4kHBgO1LW9wdJoPMruRpt3YAdAcXzI/o2g= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1741355618; c=relaxed/simple; bh=cUKKOBIA6AnCtzbT1MqxSkVVKShO6X5VCDkFmfJSlNY=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=knENDcAQGYhmCkp2z4Irwa/uXzeVs1jYdLpxZdHWJCJIRWLp9u4S6Kg5hsMJ6GCiO9T6aPwuKPZ3UoAndV9//N9c0K5QCzrmqELhzqZhzCBt5+czSvr2U9fHrP1CHupV3o8jJhFyJi1fW0HWuMDt2ghyaCg5CdxWxFNo8/Hc4tg= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=alexander.sverdlin@siemens.com header.b=AFjqASyS; arc=none smtp.client-ip=185.136.65.227 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=alexander.sverdlin@siemens.com header.b="AFjqASyS" Received: by mta-65-227.siemens.flowmailer.net with ESMTPSA id 20250307135325f67685f376872cb33d for ; Fri, 07 Mar 2025 14:53:25 +0100 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm1; d=siemens.com; i=alexander.sverdlin@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc; bh=gTZ/5YY+d6HrO592o2qXwOahDlenU2BclkBMG+f5nAs=; b=AFjqASySXU/F7WaU3Wt0kAYT03HCFqwxmmlhBTDWDO4kifKJWVilYU/SOVdWYHMD/ZSZbm EBPKeN3e0ISGtrPTTnSJPmSOxMaq08UILbi+8Kijm9SI7s6RWxlmCLnlWfcSeqCkFUaYOJiZ LCsYzQFLW/ywcNNRIcm/z1+HsP0pW7JOGDaYnOG4Y6ROtjN5U3brenYOnKcamc+ZtMhTiWo4 AAByvLuZVHQ+MIlsO3daK5L+Kn4muGfUGgx+IgMZpwmb4svtvxQbcQAuHFb6XlF9de5pMHVK apyzn+as1f5e/zEDJkm1eRlPG4QAq+rQ16G1n9CD2QxGdTsewx13BTvQ==; From: "A. Sverdlin" To: devicetree@vger.kernel.org Cc: Alexander Sverdlin , Rob Herring , Saravana Kannan , linux-kernel@vger.kernel.org Subject: [PATCH] of/irq: Refuse to of_irq_parse_one() more than one IRQ if #interrupt-cells = <0> Date: Fri, 7 Mar 2025 14:52:18 +0100 Message-ID: <20250307135231.4080272-1-alexander.sverdlin@siemens.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-456497:519-21489:flowmailer Content-Type: text/plain; charset="utf-8" From: Alexander Sverdlin An #interrupt-cells =3D <0> property may arguably be a right answer for an interrupt controller having just one interrupt and no options to configure. There are anyway already existing examples in the tree, both in DTs and in the bindings. Now the problem is that of_irq_count() called on an interrupt generating device having one of the former controllers as parent would result in an endless loop. It's especially unpleasant in the startup where of_irq_count() <=3D ... <=3D of_platform_default_populate_init() will silen= tly hang forever (unless a watchdog bites). Prevent others from spending the same time on debugging this by refusing to parse more than one IRQ for such controllers. Signed-off-by: Alexander Sverdlin --- drivers/of/irq.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/of/irq.c b/drivers/of/irq.c index 6c843d54ebb11..b3a359c7641d3 100644 --- a/drivers/of/irq.c +++ b/drivers/of/irq.c @@ -381,6 +381,13 @@ int of_irq_parse_one(struct device_node *device, int i= ndex, struct of_phandle_ar goto out; } =20 + if (!intsize && index) { + pr_debug("%pOF trying to map IRQ %d in %pOF having #interrupt-cells =3D = <0>\n", + device, index, p); + res =3D -EINVAL; + goto out; + } + pr_debug(" parent=3D%pOF, intsize=3D%d\n", p, intsize); =20 /* Copy intspec into irq structure */ --=20 2.48.1