Re: [PATCH] tpm: Make timeout logic simpler and more robust

Mimi Zohar
2019-03-12T18:32:22Z

On Tue, 2019-03-12 at 10:14 -0700, James Bottomley wrote:

> > > However, I am saying we should root cause this problem rather than
> > > take a blind shot at the apparent timeout complexity. My timeout
> > > instability is definitely related to the polling adjustments, so
> > > it's not unreasonable to think Facebooks might be as well.
> >
> > James, I thought Peter sent you a tis "debug" tool to help you debug
> > the problem you're seeing. Whatever happened?

https://patchwork.kernel.org/patch/10520247/#22107607

>
> No, not seen one. I have tried to debug the problem, but it's really
> odd: my TPM is a polled nuvoton (so no irq line). If you poll the data
> ready bit on my TPM too often, it simply drops off the bus and every
> TPM operation after that times out. The only way to recover is to
> reboot.
>
> James
>