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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 A6BE7C432C3 for ; Thu, 14 Nov 2019 16:48:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 7BBAC206DC for ; Thu, 14 Nov 2019 16:48:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726632AbfKNQsq (ORCPT ); Thu, 14 Nov 2019 11:48:46 -0500 Received: from mga01.intel.com ([192.55.52.88]:41737 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726214AbfKNQsq (ORCPT ); Thu, 14 Nov 2019 11:48:46 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from orsmga005.jf.intel.com ([10.7.209.41]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 14 Nov 2019 08:48:45 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.68,304,1569308400"; d="scan'208";a="379628441" Received: from pkamlakx-mobl1.gar.corp.intel.com (HELO localhost) ([10.252.10.73]) by orsmga005.jf.intel.com with ESMTP; 14 Nov 2019 08:48:43 -0800 Date: Thu, 14 Nov 2019 18:48:41 +0200 From: Jarkko Sakkinen To: Stefan Berger Cc: linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: question about setting TPM_CHIP_FLAG_IRQ in tpm_tis_core_init Message-ID: <20191114164841.GD9528@linux.intel.com> References: <20191112033637.kxotlhm6mtr5irvd@cantor> <20191112200703.GB11213@linux.intel.com> <20191112201734.sury5nd3cptkckgb@cantor> <50290fc8-4d22-3eb5-c930-079f8b819a8e@linux.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <50290fc8-4d22-3eb5-c930-079f8b819a8e@linux.ibm.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org On Tue, Nov 12, 2019 at 03:30:51PM -0500, Stefan Berger wrote: > On 11/12/19 3:17 PM, Jerry Snitselaar wrote: > > On Tue Nov 12 19, Jarkko Sakkinen wrote: > > > On Mon, Nov 11, 2019 at 08:36:37PM -0700, Jerry Snitselaar wrote: > > > > Question about 1ea32c83c699 ("tpm_tis_core: Set TPM_CHIP_FLAG_IRQ > > > > before probing for interrupts").  Doesn't tpm_tis_send set this flag, > > > > and setting it here in tpm_tis_core_init short circuits what > > > > tpm_tis_send was doing before? There is a bug report of an interrupt > > > > storm from a tpm on a t490s laptop with the Fedora 31 kernel (5.3), > > > > and I'm wondering if this change could cause that. Before they got the > > > > warning about interrupts not working, and using polling instead. > > > > > > Looks like it. Stefan? > > > > > > /Jarkko > > > > > > > Stefan is right about the condition check at the beginning of > > tpm_tis_send. > > > >     if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested) > >         return tpm_tis_send_main(chip, buf, len); > > > > Before his change it would've gone straight to calling > > tpm_tis_send_main instead of jumping down and doing the irq test, due > > to the flag not being set. With his change it should now skip this > > tpm_tis_send_main call when tpm_tis_gen_interrupt is called, and then > > after that time through tpm_tis_send priv->irq_tested will be set, and > > the flag should be set as to whether or not irqs were working. > > > > I should hopefully have access to a t490s in a few days so I can look at > > it, > > and try to figure out what is happening. > > > I hope the t490s is an outlier. Give the patch I just posted a try. First I must be first that it is the best way to fix the bug. Also, it did not have fixes tag. /Jarkko