lists.openwall.net   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, 1 Mar 2017 14:39:09 -0800
From:   Sonny Rao <sonnyrao@...omium.org>
To:     Jason Gunthorpe <jgunthorpe@...idianresearch.com>
Cc:     Mark Rutland <mark.rutland@....com>,
        Enric Balletbo i Serra <enric.balletbo@...labora.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        Rob Herring <robh+dt@...nel.org>,
        tpmdd-devel@...ts.sourceforge.net
Subject: Re: [tpmdd-devel] [PATCH] tpm: do not suspend/resume if power stays on

On Wed, Mar 1, 2017 at 10:43 AM, Jason Gunthorpe
<jgunthorpe@...idianresearch.com> wrote:
>> > +Optional properties:
>> > +- powered-while-suspended: present when the TPM is left powered on between
>> > +  suspend and resume (makes the suspend/resume callbacks do nothing).
>>
>> This reads like configuration rather than a HW property.
>
> I read this to mean the HW does not cut power to the TPM when Linux
> does 'suspend'.

That's correct, it is a hardware property describing whether power is
removed during suspend.

>
> We recently added global suspend/resume callbacks to the TPM
> core. Those call backs do not power off the TPM, they just prepare its
> internal state to loose power to the chip. Skipping that process on
> hardware that does not power-off the TPM makes sense to me.
>
> But, Sonny, perhaps this should be a global flag in tpm_chip, not a
> per-interface-driver override?

It's a property of the board design not the chip -- maybe I'm misunderstanding?

>
> Jason

Powered by blists - more mailing lists