Re: [PATCH] tpm_tis: Re-enable interrupts upon resume

[Stefan Berger]

On 02/26/2011 06:46 AM, Jiri Slaby wrote:
> On 02/22/2011 08:49 PM, Stefan Berger wrote:
> > Below patch applies to the tip of the git tree.
> >
> > This patch makes sure that if the TPM TIS interface is run in interrupt
> > mode (rather than polling mode) that the interrupts are enabled in the
> > TPM's interrupt enable register which may either have been cleared by
> > the TPM's TIS loosing its state during device sleep in ACPI S3 (suspend)
> > or by the BIOS, which upon resume sends a TPM_Startup() command to the
> > TPM, and may run the TPM in polling mode and leave the TIS interrupts
> > disabled once it transfers control to the OS again.
> >
> > Problem is, I don't currently have a machine running the TPM in
> > interrupt mode. I found this through a self-built TPM device model for
> > Qemu and SeaBIOS patches, where this does resolve a problem upon resume.
> >
> > You may want to check if your TPM runs with interrupts by doing
> >
> > cat /proc/interrupts | grep -i tpm
> No, this is empty output.
Ok. That's what most TPM seem to do now -- they run in polling mode.

  Stefan

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