Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752157AbaLNPkL (ORCPT ); Sun, 14 Dec 2014 10:40:11 -0500 Received: from mga01.intel.com ([192.55.52.88]:43797 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750824AbaLNPkJ (ORCPT ); Sun, 14 Dec 2014 10:40:09 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,575,1413270000"; d="scan'208";a="637391094" Date: Sun, 14 Dec 2014 17:40:03 +0200 From: Jarkko Sakkinen To: Stefan Berger Cc: Peter Huewe , Ashley Lai , Marcel Selhorst , tpmdd-devel@lists.sourceforge.net, linux-kernel@vger.kernel.org, josh@joshtriplett.org, christophe.ricard@gmail.com, jason.gunthorpe@obsidianresearch.com, linux-api@vger.kernel.org, trousers-tech@lists.sourceforge.net, Will Arthur Subject: Re: [PATCH v10 8/8] tpm: TPM 2.0 FIFO Interface Message-ID: <20141214154003.GA13338@intel.com> References: <1418413600-5400-1-git-send-email-jarkko.sakkinen@linux.intel.com> <1418413600-5400-9-git-send-email-jarkko.sakkinen@linux.intel.com> <548DA33A.4010300@linux.vnet.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <548DA33A.4010300@linux.vnet.ibm.com> Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Dec 14, 2014 at 09:48:26AM -0500, Stefan Berger wrote: > On 12/12/2014 02:46 PM, Jarkko Sakkinen wrote: > >Detect TPM 2.0 by sending idempotent TPM 2.x command. Ordinals for > >TPM 2.0 are higher than TPM 1.x commands so this should be fail-safe. > >Using STS3 is unreliable because some chips just report 0xff and not > >what the spec says. > > TPM TIS 1.2 can report either 0xff or 0x00 for sts3 since that part of > register was not defined for this version but only for a later version. So, > unless the TIS 1.3 for TPM 2.0 is broken, it should report a bit _pattern_ > (not plain 0x00 or 0xff) that you could apply the suggested mask to and > check then. I propose this: lets keep the bit ugly but approach for now and when there are TPM2 FIFOs available in the market move to your workaround. I think that would be the most reasonable middle road here. > Stefan /Jarkko -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/