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,URIBL_BLOCKED,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 C70ADC17441 for ; Tue, 12 Nov 2019 15:35:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id A94A421783 for ; Tue, 12 Nov 2019 15:35:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727324AbfKLPfx (ORCPT ); Tue, 12 Nov 2019 10:35:53 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:50830 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726376AbfKLPfx (ORCPT ); Tue, 12 Nov 2019 10:35:53 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.27/8.16.0.27) with SMTP id xACFTHiM008173; Tue, 12 Nov 2019 10:35:45 -0500 Received: from ppma04wdc.us.ibm.com (1a.90.2fa9.ip4.static.sl-reverse.com [169.47.144.26]) by mx0b-001b2d01.pphosted.com with ESMTP id 2w7wqk4u6p-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 Nov 2019 10:35:45 -0500 Received: from pps.filterd (ppma04wdc.us.ibm.com [127.0.0.1]) by ppma04wdc.us.ibm.com (8.16.0.27/8.16.0.27) with SMTP id xACFUOEj003050; Tue, 12 Nov 2019 15:35:44 GMT Received: from b01cxnp23034.gho.pok.ibm.com (b01cxnp23034.gho.pok.ibm.com [9.57.198.29]) by ppma04wdc.us.ibm.com with ESMTP id 2w5n35yukr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Tue, 12 Nov 2019 15:35:44 +0000 Received: from b01ledav004.gho.pok.ibm.com (b01ledav004.gho.pok.ibm.com [9.57.199.109]) by b01cxnp23034.gho.pok.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id xACFZhxK50397546 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Nov 2019 15:35:43 GMT Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 461E6112061; Tue, 12 Nov 2019 15:35:43 +0000 (GMT) Received: from b01ledav004.gho.pok.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 30016112062; Tue, 12 Nov 2019 15:35:43 +0000 (GMT) Received: from sbct-3.pok.ibm.com (unknown [9.47.158.153]) by b01ledav004.gho.pok.ibm.com (Postfix) with ESMTP; Tue, 12 Nov 2019 15:35:43 +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> <6d6f0899-8ba0-d6cf-ef3b-317ca698b687@linux.ibm.com> <20191112142418.3wwa4iukas4h2glp@cantor> From: Stefan Berger Message-ID: <23360efd-131d-d696-220e-0cdb388a0201@linux.ibm.com> Date: Tue, 12 Nov 2019 10:35:42 -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: <20191112142418.3wwa4iukas4h2glp@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_05:,, 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=883 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1910280000 definitions=main-1911120134 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/12/19 9:24 AM, Jerry Snitselaar wrote: > On Tue Nov 12 19, Stefan Berger wrote: >> On 11/11/19 10:36 PM, 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. >>> >> I set this flag for the TIS because it wasn't set anywhere else. >> tpm_tis_send() wouldn't set the flag but go via the path: >> >> if (!(chip->flags & TPM_CHIP_FLAG_IRQ) || priv->irq_tested) >> >>         return tpm_tis_send_main(chip, buf, len); >> >> the only other line for the TIS to set the IRQ flag was in the same >> function further below, though that wouldn't be reached due to the >> above: >> >> [...] >> >> priv->irq = irq; >> >> chip->flags |= TPM_CHIP_FLAG_IRQ; >> >> >>    Stefan >> >> > > Ugh, you're right I was reading that as ! around both the flag and > priv->irq_tested. > > Should the flag be cleared if tpm_tis_probe_irq_single fails prior to > calling > tpm_tis_gen_interrupt? > The disable_interrupts() should be called to reset the flag if, while probing, the interrupt handler wasn't called. Maybe that t490s returns either via this path https://elixir.bootlin.com/linux/latest/source/drivers/char/tpm/tpm_tis_core.c#L631 or this one here https://elixir.bootlin.com/linux/latest/source/drivers/char/tpm/tpm_tis_core.c#L634 thinking the (shared) interrupt is not for it?! But this would mean TPM_INT_STATUS is broken...