lkml.org 
[lkml]   [2017]   [Mar]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Date
SubjectRe: [tpmdd-devel] [PATCH] tpm: do not suspend/resume if power stays on
On Wed, Mar 1, 2017 at 10:43 AM, Jason Gunthorpe
<jgunthorpe@obsidianresearch.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

\
 
 \ /
  Last update: 2017-03-01 23:40    [W:0.058 / U:0.124 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site