lists  /  announce  owl-users  owl-dev  john-users  john-dev  passwdqc-users  yescrypt  popa3d-users  /  oss-security  kernel-hardening  musl  sabotage  tlsify  passwords  /  crypt-dev  xvendor  /  Bugtraq  Full-Disclosure  linux-kernel  linux-netdev  linux-ext4  linux-hardening  linux-cve-announce  PHC 
Open Source and information security mailing list archives
Hash Suite: Windows password security audit tool. GUI, reports in PDF.
[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Date:   Wed, 20 Dec 2017 19:33:26 +0100
From:   Javier Martinez Canillas <>
To:     Jason Gunthorpe <>
Cc:     "Shaikh, Azhar" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>,
        "" <>
Subject: Re: [PATCH 0/4] tpm: fix PS/2 devices not working on Braswell systems
 due CLKRUN enabled

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

Powered by blists - more mailing lists