linux-kernel - RE: [PATCH v3] tpm: Enable CLKRUN protocol for Braswell systems

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Message-ID: <5FFFAD06ADE1CA4381B3F0F7C6AF5828910FC0@ORSMSX109.amr.corp.intel.com>
Date:   Thu, 8 Jun 2017 19:27:34 +0000
From:   "Shaikh, Azhar" <azhar.shaikh@...el.com>
To:     Alan Cox <gnomes@...rguk.ukuu.org.uk>,
        Jason Gunthorpe <jgunthorpe@...idianresearch.com>
CC:     "jarkko.sakkinen@...ux.intel.com" <jarkko.sakkinen@...ux.intel.com>,
        "tpmdd-devel@...ts.sourceforge.net" 
        <tpmdd-devel@...ts.sourceforge.net>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "linux-security-module@...r.kernel.org" 
        <linux-security-module@...r.kernel.org>
Subject: RE: [PATCH v3] tpm: Enable CLKRUN protocol for Braswell systems



> -----Original Message-----
> From: Alan Cox [mailto:gnomes@...rguk.ukuu.org.uk]
> Sent: Thursday, June 8, 2017 11:50 AM
> To: Jason Gunthorpe <jgunthorpe@...idianresearch.com>
> Cc: Shaikh, Azhar <azhar.shaikh@...el.com>;
> jarkko.sakkinen@...ux.intel.com; tpmdd-devel@...ts.sourceforge.net; linux-
> kernel@...r.kernel.org; linux-security-module@...r.kernel.org
> Subject: Re: [PATCH v3] tpm: Enable CLKRUN protocol for Braswell systems
> 
> > For that purpose all that should be required is strong ordering of the
> > outb relative to the other TPM commands at the LPC interface FIFO. I
> > also think the wmb is not needed because outb is already defined to be
> > strongly in order with respect to writel/readl ?
> 
> That's my assumption but given this is all some kind of 'it's broken'
> fixup I thought best to ask. Assuming there is nothing else magical going on
> then yes it should be deleted.
> 

As Jason mentioned, outb is already define to be strongly ordered, then wmb is not needed.
I will delete it.

> Alan