linux-kernel - Re: [PATCH] tpm_tis: override reported C and D timeouts for Atmel 3203

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Date:   Fri, 13 Jan 2017 17:50:45 +0200
From:   Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To:     "Maciej S. Szmigiero" <mail@...iej.szmigiero.name>
Cc:     Jason Gunthorpe <jgunthorpe@...idianresearch.com>,
        tpmdd-devel@...ts.sourceforge.net,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Peter Huewe <peterhuewe@....de>,
        Marcel Selhorst <tpmdd@...horst.net>,
        Christophe Ricard <christophe.ricard@...il.com>
Subject: Re: [PATCH] tpm_tis: override reported C and D timeouts for Atmel
 3203

On Thu, Jan 12, 2017 at 10:37:31PM +0100, Maciej S. Szmigiero wrote:
> On 12.01.2017 21:20, Jarkko Sakkinen wrote:
> > On Thu, Jan 12, 2017 at 09:09:33PM +0100, Maciej S. Szmigiero wrote:
> >> Hi Jason,
> >>
> >> On 12.01.2017 19:42, Jason Gunthorpe wrote:
> (..)
> >>> Can you also add a check for 0 timeouts in the core code and print a
> >>> FW_BUG :\
> >>
> >> Hmm, I dug in history of tpm-interface.c and the code had actually rejected
> >> zero timeouts until commit 8e54caf407b98e (this is the commit that
> >> introduced the Atmel 3204 workaround) and let default timeout values remain
> >> instead (it looks like they were exactly like these in above override at
> >> that time).
> >>
> >> Did Atmel 3204 report wrong but non-zero timeouts?
> > 
> > Wouldn't it make more sense to fix this by re-adding this fallback?
> 
> I think it would be a cleaner fix and also catch other problematic
> devices (if there are any) without needing to add individual overrides.

Please go with that but add also FW_BUG print just to be aware of
chips that report zero values.

/Jarkko