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=-2.3 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 4DC68C17441 for ; Tue, 12 Nov 2019 21:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 2C95B20674 for ; Tue, 12 Nov 2019 21:39:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726991AbfKLVjH (ORCPT ); Tue, 12 Nov 2019 16:39:07 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:59200 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726912AbfKLVjG (ORCPT ); Tue, 12 Nov 2019 16:39:06 -0500 Received: from pps.filterd (m0098417.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xACKQcVM080297; Tue, 12 Nov 2019 15:30:53 -0500 Received: from ppma03wdc.us.ibm.com (ba.79.3fa9.ip4.static.sl-reverse.com [169.63.121.186]) by mx0a-001b2d01.pphosted.com with ESMTP id 2w820mkshg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 Nov 2019 15:30:53 -0500 Received: from pps.filterd (ppma03wdc.us.ibm.com [127.0.0.1]) by ppma03wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xACKUL5v031354; Tue, 12 Nov 2019 20:30:52 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma03wdc.us.ibm.com with ESMTP id 2w5n361vcq-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 Nov 2019 20:30:52 +0000 Received: from b01ledav006.gho.pok.ibm.com (b01ledav006.gho.pok.ibm.com [9.57.199.111]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xACKUprg32964922 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 20:30:51 GMT Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 8001FAC05E; Tue, 12 Nov 2019 20:30:51 +0000 (GMT) Received: from b01ledav006.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 728D9AC059; Tue, 12 Nov 2019 20:30:51 +0000 (GMT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b01ledav006.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 12 Nov 2019 20:30:51 +0000 (GMT) Subject: Re: question about setting TPM_CHIP_FLAG_IRQ in tpm_tis_core_init To: Jarkko Sakkinen , linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org References: <20191112033637.kxotlhm6mtr5irvd@cantor> <20191112200703.GB11213@linux.intel.com> <20191112201734.sury5nd3cptkckgb@cantor> From: Stefan Berger Message-ID: <50290fc8-4d22-3eb5-c930-079f8b819a8e@linux.ibm.com> Date: Tue, 12 Nov 2019 15:30:51 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.1.1 MIME-Version: 1.0 In-Reply-To: <20191112201734.sury5nd3cptkckgb@cantor> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:,, definitions=2019-11-12_07:,, signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=0 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 mlxscore=0 impostorscore=0 mlxlogscore=999 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120174 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.     Stefan