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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 E0D74C433DF for ; Mon, 15 Jun 2020 22:06:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C764320739 for ; Mon, 15 Jun 2020 22:06:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726044AbgFOWGb (ORCPT ); Mon, 15 Jun 2020 18:06:31 -0400 Received: from mga11.intel.com ([192.55.52.93]:20447 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725903AbgFOWGa (ORCPT ); Mon, 15 Jun 2020 18:06:30 -0400 IronPort-SDR: YZR7bszmZI5zPaSEhXr2UsYzaWvHvpYegJKhzJcmA354T3UqMxNWavX+6MAQlRFoEGKNVibGCa kELfQO3JrhVg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga102.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 15 Jun 2020 15:06:29 -0700 IronPort-SDR: g7pM/5WnFQJIjyB0RQlgJAmGUH6fUjSCqY4dAyK4mygQS7uo9hM8YJMDe3fnmMNIYehiwGlHkK acMDTWqric+A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,516,1583222400"; d="scan'208";a="476183583" Received: from ifaivilx-mobl.ger.corp.intel.com (HELO localhost) ([10.249.35.251]) by fmsmga006.fm.intel.com with ESMTP; 15 Jun 2020 15:06:24 -0700 Date: Tue, 16 Jun 2020 01:06:25 +0300 From: Jarkko Sakkinen To: Jerry Snitselaar Cc: Hans de Goede , Peter Huewe , Jason Gunthorpe , Stefan Berger , Arnd Bergmann , Greg Kroah-Hartman , linux-integrity@vger.kernel.org, Mark Pearson Subject: Re: [PATCH] tpm_tis_core: Disable broken IRQ handling code Message-ID: <20200615220625.GA25252@linux.intel.com> References: <20200409211044.21625-1-hdegoede@redhat.com> <20200410210652.GA16905@linux.intel.com> <20200604091712.qvcqkkhhtcqoorpd@cantor> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200604091712.qvcqkkhhtcqoorpd@cantor> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Thu, Jun 04, 2020 at 02:17:12AM -0700, Jerry Snitselaar wrote: > On Thu May 07 20, Hans de Goede wrote: > > Hi All, > > > > On 4/10/20 11:06 PM, Jarkko Sakkinen wrote: > > > On Thu, Apr 09, 2020 at 11:10:44PM +0200, Hans de Goede wrote: > > > > Since commit dda8b2af395b ("tpm: Revert "tpm_tis_core: Set > > > > TPM_CHIP_FLAG_IRQ before probing for interrupts"") we no longer set > > > > the TPM_CHIP_FLAG_IRQ ever. > > > > > > > > So the whole IRQ probing code is not useful, worse we rely on the > > > > IRQ-test path of tpm_tis_send() to call disable_interrupts() if > > > > interrupts do not work, but that path never gets entered because we > > > > never set the TPM_CHIP_FLAG_IRQ. > > > > > > > > So the remaining IRQ probe code calls request_irq() and never calls > > > > free_irq() even when the interrupt is not working. > > > > > > > > On some systems, e.g. the Lenovo X1 8th gen, the interrupt we try > > > > to use and never free creates an interrupt storm followed by > > > > an "irq XX: nobody cared" oops. > > > > > > > > Since it is non-functional at the moment anyways, lets just completely > > > > disable the IRQ code in tpm_tis_core for now. > > > > > > > > Fixes: dda8b2af395b ("tpm: Revert "tpm_tis_core: Set TPM_CHIP_FLAG_IRQ before probing for interrupts"") > > > > Signed-off-by: Hans de Goede > > > > --- > > > > Note I'm working with Lenovo to try and get to the bottom of this. > > > > --- > > > > > > OK if I recall correctly the reason for reverting was that the fixes > > > Stefan was sending were broken and no access to hardware were the > > > issues would be visible. The reason for not doing anything til this > > > day is that we don't have T490 available. > > > > So as promised I have been in contact with Lenovo about this. > > > > Specifically I have been in contact with Lenovo about seeing an > > IRQ storm when the tpm_tis code tries to use the IRQ on a X1 carbon > > 8th gen (X1C8), because of the now public plan that Lenovo will > > offer ordering this model with Fedora pre-installed: > > https://lwn.net/Articles/818595/ > > > > On the X1C8 the problem has been diagnosed to be a misconfigured > > GPIO pin on the CPU (the SoC). The X1C8 uses an SPI connected > > TPM chip with its IRQ connected to a GPIO on the SoC which is > > configured in Direct IRQ mode, so that it directly asserts > > IRQs on one of the APIC IRQs. The problem is that due to the > > misconfiguration as soon as the IRQ is enabled it fires > > continuously. > > > > For the X1C8 this should be fixed in the BIOS of the first > > batch which gets shipped out to customers so there we should > > not have to worry about this. > > > > It is likely (but not yet confirmed) that the issue on the T490 > > is the same, although on my test X1C8 device I got an IRQ storm, > > followed by the kernel disabling the IRQ, not a non booting system. > > I guess this might be due to kernel configuration differences. > > > > Assuming that the issue on the T490 is the same, we might see a > > BIOS update fixing this, but given that non-booting is > > 'not good ("tm")' even if there will be a BIOS fix we should > > still do something at the kernel level to also work with the > > older unfixed BIOS which is already out there. > > > > I've been thinking about this and I'm afraid that the only thing > > what we can do is add a DMI product-name (product-version for Lenovo) > > string based blacklist for IRQ usage to drivers/char/tpm/tpm_tis.c > > and set tpm_info.irq = -1 for devices on that list. > > > > My plan is to prepare a RFC patch of such a blacklist, while we > > wait for confirmation that the root cause on the T490 is the same > > as on the X1C8, but before I work on that I'm wondering if > > people agree that that is the best approach, or if there are > > other suggestions for dealing with this ? > > > > Regards, > > > > Hans > > > > Jarrko, > > Any thoughts about how we should move forward on dealing with this? > I've got a report about the original problem Stefan was dealing with, > where the tpm isn't powered on when it tries to send a command to > generate an interrupt. The tpm is functioning so it isn't urgent, > but it would be good to get this cleaned up so users aren't getting > transmit errors and firmware bug messages. Hans did you make any > progress on the blacklist patch? We need the blacklist. Up until that warnings is the best we can do. /Jarkko