On Fri, Jun 26, 2020 at 08:25:57AM -0400, Stefan Berger wrote:

quoted

I don't think the tpm driver was ever designed for edge, so most
likely the structure and order of the hard irq is not correct.

Right. For edge support I think we would need to avoid causing another
interrupt (like locality change interrupt) before the interrupt handler
hasn't finished dealing with an existing interrupt. Considering that Windows
works on IRQ 13 (egde) and Linux driver cannot, I guess this is a good
reason not to move QEMU TIS to IRQ 13 and try to support interrupts via ACPI
table declaration.

Generaly clearing the IRQ needs to be done before testing for pending
IRQs - ie as the first thing

Move the write to status up higher:

	rc = tpm_tis_read32(priv, TPM_INT_STATUS(priv->locality), &interrupt);
	rc = tpm_tis_write32(priv, TPM_INT_STATUS(priv->locality), interrupt);
	
        [handle 'interrupt']

Then if new events set a status bit they will generate an edge and
re-enter here.

I don't know why there is an extra read at the end of the handler
either, seems sketchy.

Jason