Re: intermittent suspend problem again

[Ferenc Wagner <wferi@niif.hu>]

Ferenc Wagner <wferi@niif.hu> writes:

> Ferenc Wagner <wferi@niif.hu> writes:
>
>> "Rafael J. Wysocki" <rjw@sisk.pl> writes:
>>
>>> On Wednesday 18 November 2009, Ferenc Wagner wrote:
>>>
>>>> Ferenc Wagner <wferi@niif.hu> writes:
>>>> 
>>>> Side question: If I run s2disk from the init=/bin/bash prompt, the
>>>> instrumentation in acpi_enter_sleep_state_prep in drivers/acpi/acpica/hwsleep.c
>>>> fires before the "Snapshotting system" phase, but it does not fire if I
>>>> hibernate from the full running desktop.  (That instrumentation was put
>>>> there to investigate the KMS-triggered STR freeze.)  What could explain
>>>> this?
>>>
>>> It looks like it uses the "shutdown" method when run with init=/bin/bash, but
>>> I don't know why exactly.
>>
>> Thanks for the tip, I'll check this too.
>
> While looking into this, I found a reproducible kernel panic:
>
> 1. boot with init=/bin/bash
> 2. mount /usr; swapon -a
> 3. plug in a USB pendrive
> 4. s2disk (machine goes to sleep)
> 5. power on, proceed with resuming, press Enter to cancel resume pause
> 6. ACPI: Hardware changed while hibernated, cannot resume!
>    Kernel panic - not syncing: ACPI S4 hardware signature mismatch
>
> Does it make sense?

Yes it does: it's the BIOS USB support playing its childish games.
I can disable it most of the time, except when booting from USB...

I wonder if this problem sould be handled more gracefully, now that USB
persistence is enabled by default.  It works just fine for STR, but
potentially panics after hibernation.
-- 
Regards,
Feri.