From nobody Sat Feb 7 11:53:21 2026 Received: from linux.microsoft.com (linux.microsoft.com [13.77.154.182]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 4205713B2B8 for ; Thu, 9 Jan 2025 18:40:22 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=13.77.154.182 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736448023; cv=none; b=sc/bR2BQx9kj3aRs8kDwd5mR3VjPIq1/wOTYD+pcFeTf/Hj1msmuxixXjAtVzreC87IJtqTScNGlshqkyHMbPyOBMn+Rl48mfn+56VwqqTkcbx81FMdCpMHmStlhdIj7vt/p6+h5C7lrFaDyBiuta6ti7eTdrVeSJ9gUQlDuyVk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736448023; c=relaxed/simple; bh=+PABFyTiopRgf3UO5wKFWJxEYEMXDppWMLF276bHR9Y=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=jEs5uScm9zg59nkg1c5DyT6oFgC0J4gm8YgyIkReqYmYWDQIwsmffL44zvGGDFllHqSHbPLOopepbRHM3Ow6eV6GBdcIxzzCm6vZtTQPYUM3TFv8y+cMaZMO1pfP2z8EEvRAmg7QxYv5+GzfJ+cNzkThQ+fw0f1+QeE1Wens3YY= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com; spf=pass smtp.mailfrom=linux.microsoft.com; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b=YFGmi3ex; arc=none smtp.client-ip=13.77.154.182 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.microsoft.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.microsoft.com header.i=@linux.microsoft.com header.b="YFGmi3ex" Received: from romank-3650.corp.microsoft.com (unknown [131.107.160.188]) by linux.microsoft.com (Postfix) with ESMTPSA id 2226A203E39F; Thu, 9 Jan 2025 10:40:16 -0800 (PST) DKIM-Filter: OpenDKIM Filter v2.11.0 linux.microsoft.com 2226A203E39F DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.microsoft.com; s=default; t=1736448016; bh=J6WWqRDVzFT6UGIy8DsAO142CsSAQp/8ZkMdBV3krtw=; h=From:To:Cc:Subject:Date:From; b=YFGmi3ex/X7Q3NoJCoSdEi97nzk2bwaPHZaiNrpVOK/eUqaixDHBWul25hXRozUS5 0me+ql+5rXDW5WD3aEINCSmhzvBHrZsUtEQPLAiwW8XsCyLZZSqNntY8QyAs3XLWf8 Np8gPffqUliWYsEFcTeqtRWDntBBP3ZF7tnsnJBE= From: Roman Kisel To: bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, ilpo.jarvinen@linux.intel.com, mingo@redhat.com, robh@kernel.org, sboyd@kernel.org, ssengar@linux.microsoft.com, tglx@linutronix.de, usamaarif642@gmail.com, x86@kernel.org, linux-kernel@vger.kernel.org Cc: apais@microsoft.com, benhill@microsoft.com, ssengar@microsoft.com, sunilmut@microsoft.com, vdso@hexbites.dev Subject: [PATCH] x86/of: Don't log error on the missing IO-APIC unconditionally Date: Thu, 9 Jan 2025 10:40:15 -0800 Message-Id: <20250109184015.1674388-1-romank@linux.microsoft.com> X-Mailer: git-send-email 2.34.1 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 Content-Type: text/plain; charset="utf-8" The x86 OF code reports the missing IO-APIC wihtout any checks whether the IO-APIC presence is required or not. That is due to that part of the code being dovetailed to the Intel MID platform. Check if the IO-APIC must be available. Log the error only when the IO-APIC is expected to be present. Signed-off-by: Roman Kisel --- arch/x86/kernel/devicetree.c | 25 +++++++++++++++++++++---- 1 file changed, 21 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/devicetree.c b/arch/x86/kernel/devicetree.c index 59d23cdf4ed0..5b3b47930d1c 100644 --- a/arch/x86/kernel/devicetree.c +++ b/arch/x86/kernel/devicetree.c @@ -47,6 +47,15 @@ static struct of_device_id __initdata ce4100_ids[] =3D { {}, }; =20 +static bool falconfalls_compatible(void) +{ + if (!of_have_populated_dt()) + return false; + + return of_flat_dt_is_compatible( + of_get_flat_dt_root(), "intel,falconfalls"); +} + static int __init add_bus_probe(void) { if (!of_have_populated_dt()) @@ -259,12 +268,20 @@ static void __init dtb_ioapic_setup(void) =20 for_each_compatible_node(dn, NULL, "intel,ce4100-ioapic") dtb_add_ioapic(dn); + if (!nr_ioapics && falconfalls_compatible()) + pr_err("Error: No information about IO-APIC in OF.\n"); =20 - if (nr_ioapics) { + if (nr_ioapics) of_ioapic =3D 1; - return; - } - pr_err("Error: No information about IO-APIC in OF.\n"); + + /* + * At this point, it might so happen that no IO-APIC has been discovered. + * + * A general assumption would be that most x86 boards have IO-APIC, + * yet that is not something the kernel should report as a firmware + * bug unconditionally as there are setups (VMs would be an easy example) + * that are able to employ other means of interrupt routing. + */ } #else static void __init dtb_ioapic_setup(void) {} base-commit: eea6e4b4dfb8859446177c32961c96726d0117be --=20 2.34.1