Re: HPET and IRQs

Chen, Zide

Hi Tomasz,

Additional to Like's comments, to calibrate the timer, if you have serial HV console, you can get the TSC frequency from the log. For example:
calibrate_tsc, tsc_khz=1593600

Then you need to change the Zephyr code accordingly. In this example, set CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC=1593600000

Best Regards,

-----Original Message-----
From: acrn-users@... <acrn-users@...> On Behalf Of Tomasz Bursztyka
Sent: Tuesday, April 28, 2020 5:19 AM
To: acrn-users@...
Subject: [acrn-users] HPET and IRQs


I am currently trying to fix an issue with Zephyr running as UOS.

The default configuration of Zephyr for acrn enables the LOAPIC timer,
but there does not seem to be any mention of such timer in acrn. Unless
I am missing something.
When running zephyr with such timer, the timing get all bogus. 60
seconds looks like 5 seconds, etc... Timings are all off.

As HPET is supported by acrn, I switched the timer to HPET. But now I
have a new issue, acrn-dm displays:

hpet t0 configured invalid irq 2, allowed_irqs 0xff000000

And nothing proceeds, since acrn defaults to 0, zephyr isr for hpet is
never called.

Indeed Zephyr sets HPET IRQ to 2, which seems to be wrong then for acrn

Which IRQ should HPET timer be configured to use on UOS side then?



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