can't mount root disk with ACPI enabled

[Sepherosa Ziehau]

On Thu, Jun 4, 2009 at 2:28 PM, Johannes Hofmann
<johannes.hofmann at gmx.de> wrote:
> Sepherosa Ziehau <sepherosa at gmail.com> wrote:
>>>
>>> Just noticed that even with revision
>>> 7e7d17cb48838b48389fb990950f2959b9635e63
>>> I still can't mount the root disk iff I load usb modules (usb, ehci,
>>> umass) during boot via /boot/loader.conf - which I normally don't to
>>> allow CPU to enter C3 state.
>>
>> You box is UP, so only i8254 is used.  C3 does not affect the i8254
>> interrupt timer.
>
> Right, but usb modules prevent the CPU from entering C3 generally
> (As far as I know it's a bus mastering DMA thing).
>
>>
>>>
>>> So maybe this is just some sort of timing problem?
>>> Is anyone else seeing this? I guess thinkpads are quite common here.
>>
>> This looks very strange, could you give me the bootverbose dmesgs:
>> w/ ACPI, w/o usb modules
>
> http://leaf.dragonflybsd.org/~hofmann/acpi_nousb.dmesg
>
>> w/o ACPI, w/ usb modules
>
> http://leaf.dragonflybsd.org/~hofmann/noacpi_usb.dmesg
>
>> I think using these two combinition, your box is booting?

Is ad0 detected w/ ACPI and w/ usb modules?

Best Regards,
sephe

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