From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.10]) (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 A8B5F1E7C12 for ; Sun, 21 Jun 2026 01:29:21 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.10 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782005364; cv=none; b=pX530tNXRH7SelUUJHrT9jB1eH6NdzpOiG7ozsvN+/+1qjuLLllmcYMEtQTlGQAnaJCbAOMbUL6ZSI/3tPNe4LvdoK3QfsHNtyNqEKbZTIbNn4jU6+me3WEnpLqhgH2MKqGCx0uJwGFYxbjnwwRi8cDZ90pLykp/u13Iplkg3Fs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782005364; c=relaxed/simple; bh=n4gcNnjcoEFUDh49zhBMUkrMqns10GW7OqVmBxWbF9o=; h=Message-ID:Date:MIME-Version:Cc:Subject:To:References:From: In-Reply-To:Content-Type; b=EDM8jPAUlfUppDF6UTCD4jyytKAz0AQRrTE/lRYcWESuNpmOpmAb19MaIqXtIodegDHGUDcFM1KkPXF8vOSlbEMFgURDLc+nO+9tGKCEWau0cXtCMbY/Gvj14616+E8X9+auHSWnY5oxnLKjS24fF0Wr8pqX+3UhprSB8YLwAHU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com; spf=pass smtp.mailfrom=linux.intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=l5YeH3m+; arc=none smtp.client-ip=192.198.163.10 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="l5YeH3m+" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1782005362; x=1813541362; h=message-id:date:mime-version:cc:subject:to:references: from:in-reply-to:content-transfer-encoding; bh=n4gcNnjcoEFUDh49zhBMUkrMqns10GW7OqVmBxWbF9o=; b=l5YeH3m+GwldakurhcCsaoIoA3+fQ4YYnqXm7eLqZclxdwWdvo6fZH/V HuvS2GHBeFvjhPWo80ZXhziwVrToB/8TxD5DIPI0gD6jwXfentslKBiEs 94M55Ne49azrErWURWgQuFsvOG257xOInEs4Nby4xmxRtW+qWPM8T54ML ELhWmPEGnpn/85qxKF7B5nnGILZEcu8GdrRwEmuWTvFAaLlIFLTJuT7gr aBsHzV+2VXU4uutJj9SHgXSiQexMlTvonY7IjDYbjs1lD3GocT+p4UJUV U4/pg96CPxU5xlzOHPgCJFZq6sx9o7uAdpuS5niUpfHLwgI1NWhFNVl5d A==; X-CSE-ConnectionGUID: nPtYAMcYRJq8jzG91ovgxQ== X-CSE-MsgGUID: k6mQqrblSW6tl0nQN4qapA== X-IronPort-AV: E=McAfee;i="6800,10657,11823"; a="94174144" X-IronPort-AV: E=Sophos;i="6.24,216,1774335600"; d="scan'208";a="94174144" Received: from orviesa006.jf.intel.com ([10.64.159.146]) by fmvoesa104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2026 18:29:20 -0700 X-CSE-ConnectionGUID: 7zdPoMnUSXq4ldov9AXttg== X-CSE-MsgGUID: 1xP/+pxHTNyhRK8CyDOuwA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,216,1774335600"; d="scan'208";a="247770672" Received: from unknown (HELO [10.238.9.114]) ([10.238.9.114]) by orviesa006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 20 Jun 2026 18:29:18 -0700 Message-ID: <7ebdaa50-2048-486e-9da4-145cea4e3753@linux.intel.com> Date: Sun, 21 Jun 2026 09:29:15 +0800 Precedence: bulk X-Mailing-List: iommu@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Cc: baolu.lu@linux.intel.com, joro@8bytes.org, will@kernel.org, robin.murphy@arm.com, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: Re: [PATCH] iommu/vt-d: Disable IOMMU on Lenovo ThinkPad P50s To: Oliver Lin , dwmw2@infradead.org References: <20260620192214.923500-1-oliver@liuxiaozhen.dev> Content-Language: en-US From: Baolu Lu In-Reply-To: <20260620192214.923500-1-oliver@liuxiaozhen.dev> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 6/21/2026 3:22 AM, Oliver Lin wrote: > On Lenovo ThinkPad P50s, enabling Intel IOMMU causes TPM > initialization failures, suspend/resume issues, and prevents the > system from powering off completely. > > The system works correctly with intel_iommu=off. A locally tested > kernel with this DMI quirk also works correctly without requiring the > kernel parameter. > > Add a DMI quirk to disable Intel IOMMU on this platform. > > Link:https://bugzilla.kernel.org/show_bug.cgi?id=221674 > Signed-off-by: Oliver Lin > --- > drivers/iommu/intel/iommu.c | 19 +++++++++++++++++++ > 1 file changed, 19 insertions(+) > > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c > index 849d06dfe1ae..a072e9ef63ef 100644 > --- a/drivers/iommu/intel/iommu.c > +++ b/drivers/iommu/intel/iommu.c > @@ -278,6 +278,19 @@ static int __init intel_iommu_setup(char *str) > > return 1; > } > + > +static const struct dmi_system_id intel_iommu_broken_dmar_table[] __initconst = { > + { > + .ident = "Lenovo ThinkPad P50s", > + .matches = { > + DMI_MATCH(DMI_SYS_VENDOR, "LENOVO"), > + DMI_MATCH(DMI_PRODUCT_NAME, "20FLCTO1WW"), > + DMI_MATCH(DMI_PRODUCT_VERSION, "ThinkPad P50s"), > + }, > + }, > + {} > +}; Is this a broken ACPI DMAR table? If so, please try updating to the latest firmware. Otherwise, report the issue to the laptop vendor and ask them to resolve it, especially if they claim their product supports Linux. Thanks, baolu