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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E53B4C433FE for ; Sun, 10 Apr 2022 09:03:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236041AbiDJJFa (ORCPT ); Sun, 10 Apr 2022 05:05:30 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33674 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229921AbiDJJFY (ORCPT ); Sun, 10 Apr 2022 05:05:24 -0400 Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6E796BDCD; Sun, 10 Apr 2022 02:03:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=gmx.net; s=badeba3b8450; t=1649581382; bh=PP14lou5/93ZSwesKhs/aFkM74lBQAXbbozD+ZJY6U4=; h=X-UI-Sender-Class:Subject:To:Cc:References:From:Date:In-Reply-To; b=ZkwGSJuNfcFO7nTjEEvntg+JMEeyHNAK9nZ+ZZimKMp8Gq6y6pg8/om/eqhKTLUlR ozJm+O5ukBlOFSBeyc5D41uC+BsWweSN6dihEgvpSQwX87SuPq45qxBm+gTFjGEU1s 2P5EOKEiDqIrg0DRO6x4uBPGwu+3b0ewU4kzlfW0= X-UI-Sender-Class: 01bb95c1-4bf8-414a-932a-4f6e2808ef9c Received: from [192.168.0.33] ([46.223.3.230]) by mail.gmx.net (mrgmx105 [212.227.17.168]) with ESMTPSA (Nemesis) id 1N3bSt-1o3Z4v1Mln-010g6J; Sun, 10 Apr 2022 11:03:02 +0200 Subject: Re: [PATCH 1/5] tpm: add functions to set and unset the tpm chips reset state To: Jason Gunthorpe Cc: peterhuewe@gmx.de, jarkko@kernel.org, robh+dt@kernel.org, devicetree@vger.kernel.org, linux-integrity@vger.kernel.org, linux-kernel@vger.kernel.org, stefanb@linux.ibm.com, p.rosenberger@kunbus.com, lukas@wunner.de References: <20220407111849.5676-1-LinoSanfilippo@gmx.de> <20220407111849.5676-2-LinoSanfilippo@gmx.de> <20220407142526.GW64706@ziepe.ca> From: Lino Sanfilippo Message-ID: Date: Sun, 10 Apr 2022 11:03:01 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20220407142526.GW64706@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable X-Provags-ID: V03:K1:ITy5SCgzF2q6XF6Ozh6e95KHI6g1E9Q2aEPU72b+QaVsae4rdFe UpWzx90EakqwrUVtrwPxgBfrd/AF2Uq3k1ZUoGc9lZBi6z+51nCotcC518HIH7Slqxu2iYC /iXgE8U4Tc2howXJiTkrJveCP2SjrFv0/16udH+8886gib3VavEuoS+mVTCn0sCVpfzORpO yo0kp2eVgafG1lL19CwTw== X-UI-Out-Filterresults: notjunk:1;V03:K0:shEpdg1hFZI=:KaypvA4/ER9yIL6Rp6c2LD dMogNUJvuk5kBMe24Hv3CkktxEqBXRHwfOAkIro9PXr4JJRj2B+Tawgn9FQVlsJiz4lYyogwc dlOgiKoP1jB7ww91GUvDfLREmRL4KN9iDtTYcIDG5nfLNJR4tBW9jfQbwA1ss3S2NTfDDarmw AGSS59fTsPZACkfuZaVqYclOPY2RzkKVu7mHVq4gKhRAYlW2qBx6lvi2WzsxgnHbRol/5SXXX f/eVgy+rKvc1JAF8XpruDKbAhGYG1PPaklQ4tEuWUINX3BFEOYMCST11VRuKj65wNrLAl56JA I9kL9lB8+X72CpwveVEX0/MRyXcrpK2Bbqz3RL7hcZbYOEP9gOTaElqasd3VgXY0jROsllaMt mV1Cxjt0kd2e6JwD6wz1VyZmQogqVNnhVwyrVeMk0Xlpggw9YYQZoeQ+/MaOSRHQd2yXnE1ui COr85dYcdUBy2mVoXZBkc/Q8fGS85nnKgh6uduaw83AeSFfyu/wauDvzuVKL7hnJC1gk4IpkP S4OUBPZuqB/9kucbwnblhUSR1/7i0lel7Zdfu3mi+2D577dvdUZO3Z+NNRF81SwmjbJz12Li7 NgFIYsueUqmVvl4YPkhHjKLa/T0Nj/nkI9TBgANWjc3nP9qXVbONdCYx1F+nNi/XZ9yr7aDUI P5EkFg8S++SZqX6OHB4IU0X7JvHa67qI5eyAjX6mu8n8RsCYX3Wh7H5cBPYPGs17p8A2AYNTq NrUHszI+seXjLeicAjCBHldiU0fTyGdxQqukeJ4m7fBjmqdHm9WkxAsCSRQe2lw+19vpykbR8 emRUADabTz2Mc3bM55jIfpareb4x5W9HMPPaXSbnecar4RyBKlhCFDoLzPQL4b3Na2CbFdD9m 9d8CIhnYwl2/fmawhQtwpU2DlrFUeP/Ig2Nea2P2JwFhrYO6w3ILS3uPrH9ytHGIb/ELPqck/ EkLEr0OD55fzIpqVyNNo4GgKvoFP2VU1bnswy1T98cmsw7VgBgaoc9XbCr/i3Ykupgay1uPi2 Rm7QjcR1qsgjikDpt6ZzfW7UJ397/nN+ZS0nCw60EcGsf5ldkTpP1tBpgNlLBPzAd3Qbl3Kxt XTt6csB/4I590M= Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 07.04.22 at 16:25, Jason Gunthorpe wrote: > On Thu, Apr 07, 2022 at 01:18:45PM +0200, Lino Sanfilippo wrote: >> Currently it is not possible to set the tpm chips reset state from with= in >> the driver. This is problematic if the chip is still in reset after the >> system comes up. This may e.g. happen if the reset line is pulled into >> reset state by a pin configuration in the device tree. > > This kind of system is badly misdesigned. > > TPM PCRs fundementally cannot work if the TPM reset line is under > software control. > > Jason > you may be right about the misdesign, but as a matter of fact there are systems which have the TPMs reset line connected to a GPIO and n= ot the system reset. For those systems we should provide a way to let at leas= t the driver put the TPM out of reset (note that on those systems the TPM reset = can be triggered by software anyway by asserting/deasserting the GPIO line). Regards, Lino