Messages in this thread | | | From | Sonny Rao <> | Date | Wed, 1 Mar 2017 14:39:09 -0800 | Subject | Re: [tpmdd-devel] [PATCH] tpm: do not suspend/resume if power stays on |
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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
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