Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932379AbdLTSdc (ORCPT ); Wed, 20 Dec 2017 13:33:32 -0500 Received: from mail-wm0-f66.google.com ([74.125.82.66]:43526 "EHLO mail-wm0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755917AbdLTSd3 (ORCPT ); Wed, 20 Dec 2017 13:33:29 -0500 X-Google-Smtp-Source: ACJfBotxyrZQLvqa4zJvrL2CNIuWGhPQPT3eyjE+eLz/UNxsgUCSTqkZPvNiRqpheuFN+qjYZTlGQQ== Subject: Re: [PATCH 0/4] tpm: fix PS/2 devices not working on Braswell systems due CLKRUN enabled To: Jason Gunthorpe Cc: "Shaikh, Azhar" , "Alexander.Steffen@infineon.com" , "hdegoede@redhat.com" , "linux-kernel@vger.kernel.org" , "james@ettle.org.uk" , "arnd@arndb.de" , "jarkko.sakkinen@linux.intel.com" , "peterhuewe@gmx.de" , "gregkh@linuxfoundation.org" , "linux-integrity@vger.kernel.org" References: <20171220113538.16099-1-javierm@redhat.com> <96f3f833-22f8-5400-bd22-7c1c622bbe61@redhat.com> <5FFFAD06ADE1CA4381B3F0F7C6AF58289886F4@ORSMSX109.amr.corp.intel.com> <5FFFAD06ADE1CA4381B3F0F7C6AF58289887AA@ORSMSX109.amr.corp.intel.com> <20171220174400.GA22908@ziepe.ca> From: Javier Martinez Canillas Message-ID: <13fd882e-a387-3ba0-d6c0-83463b9d3840@redhat.com> Date: Wed, 20 Dec 2017 19:33:26 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.5.0 MIME-Version: 1.0 In-Reply-To: <20171220174400.GA22908@ziepe.ca> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1274 Lines: 32 On 12/20/2017 06:44 PM, Jason Gunthorpe wrote: > On Wed, Dec 20, 2017 at 05:45:16PM +0100, Javier Martinez Canillas wrote: > >> CHP51 says "LPC Clock Control Using the LPC_CLKRUN# May Not Behave As Expected" >> and that the implication is that "The SoC may prevent a peripheral device from >> successfully requesting the LPC clock". > > Now we are back to the beginning - the LPC_CLKRUN protocol is simply > broken in BSW chipsets, and it has nothing to do with the TPM? > > Intel is trying to work around that broken-ness and still preserve > power management in the case where only the TPM is connected to the > LPC bus.. It is questionable to me if this is even a good idea, or if > Linux is the right place to implement this work around (eg something > in SMM mode may be more appropriate for a chipset bug) > > I think your patch is still the right improvement, if the BIOS turned > the feature off, we should not turn it back on. > Yes, the patch has merits on its own since fixes a flaw in the logic of the original CLKRUN patch. I think we should merge it and then the other issues can be fixed (or rework how the CLKRUN is managed) as follow-ups. > Jason > Best regards, -- Javier Martinez Canillas Software Engineer - Desktop Hardware Enablement Red Hat