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

From: Stefan Berger
Date: Sat Feb 26 2011 - 08:50:11 EST

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.


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at
Please read the FAQ at