Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751695AbdHMXyD (ORCPT ); Sun, 13 Aug 2017 19:54:03 -0400 Received: from mx2.suse.de ([195.135.220.15]:47411 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751202AbdHMXyB (ORCPT ); Sun, 13 Aug 2017 19:54:01 -0400 Date: Mon, 14 Aug 2017 01:53:59 +0200 From: msuchanek To: Ken Goldman Cc: linux-ima-devel@lists.sourceforge.net, linux-security-module@vger.kernel.org, tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org Subject: Re: [tpmdd-devel] [PATCH] tpm: improve tpm_tis send() performance by ignoring burstcount Message-ID: <20170814015359.30177c87@naga> In-Reply-To: <9cb350b6-32fd-529e-eb31-6800339cddb2@linux.vnet.ibm.com> References: <20170807114632.1339-1-nayna@linux.vnet.ibm.com> <20170808191145.kggmoczd5laiccrn@linux.intel.com> <9cb350b6-32fd-529e-eb31-6800339cddb2@linux.vnet.ibm.com> X-Mailer: Claws Mail 3.15.0-dirty (GTK+ 2.24.31; x86_64-suse-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 925 Lines: 30 Hello, On Fri, 11 Aug 2017 17:32:12 -0400 Ken Goldman wrote: > On 8/9/2017 5:00 PM, Peter Huewe wrote: > > > > Since we are the linux kernel, we do have to care for legacy > > devices. And a system with LPC, PS2Mouse on SuperIO and a TPM are > > not that uncommon. > > > > And heck, we even have support for 1.1b TPM devices.... > > Understood. However, remember that SuperIO is a 1980's device that > predates the TPM. Since the TPM requires special LPC bus cycles, it's > even less likely that an old chipset has an attached TPM. Where are the PS/2 ports attached today? About 500 out of 700 mainboards sold today has a PS/2 port which is probably due to prevalence of legacy devices and usbhid limitations. Similarily many boards have serial and parallel hardware ports. In all diagrams detailed enough to show these ports I have seen them attached to the LPC bus. Thanks Michal