Ferenc Wagner <wferi@xxxxxxx> writes:
> "Rafael J. Wysocki" <rjw@xxxxxxx> writes:
>
>> On Wednesday 18 November 2009, Ferenc Wagner wrote:
>>
>>> Ferenc Wagner <wferi@xxxxxxx> writes:
>>>
>>>> Since I've instrumented s2disk and the hibernation path, no freeze
>>>> happened during hibernating the machine.
>>>
>>> Not until I removed the delays from hibernation_platform_enter(), which
>>> were put there previously to get step-by-step feedback. Removing them
>>> again resulted in a freeze in short course, maybe just two hibernations
>>> later. The instrumentation shows it stuck in dpm_suspend_start(PMSG_HIBERNATE).
>>> Does it mean that some device driver is at fault?
>>
>> A driver or one of the platform hooks.
This result (the freeze happens in dpm_suspend_start) may not stand
anymore: the parport_pc module was loaded and this falsified my results.
That is, after suspending that device, the parport feedback ceased
working, outbs becoming ineffective.
>>> I'll check if it always fails at the same point (although tracing into
>>> dpm_suspend_start isn't pure fun because of the multitude of devices it
>>> loops over). Is there any way to get printk output from that phase?
>>
>> Compile with CONFIG_PM_VERBOSE (it does mean exactly that).
>
> I've been running with CONFIG_PM_VERBOSE=y for a good while, but that
> didn't help getting for example the result of the following printks to
> the VGA console (0x3bc is the parallel port):
>
> @@ -445,34 +446,66 @@ int hibernation_platform_enter(void)
> * hibernation_ops->finish() before saving the image, so we should let
> * the firmware know that we're going to enter the sleep state after all
> */
> + printk ("hibernation_ops->begin()...\n");
> + outb(16, 0x3bc);
> error = hibernation_ops->begin();
> + outb(17, 0x3bc);
> + printk ("hibernation_ops->begin(): %d\n", error);
> if (error)
> goto Close;
The problem was the very low (1) default suspend loglevel. After
raising it, the incriminated messages (and lots of other stuff)
appeared.
> However, my dmesg is full of lines like
>
> agpgart-intel 0000:00:00.0: preparing freeze
> pci 0000:00:00.1: preparing freeze
> pci 0000:00:00.3: preparing freeze
>
> etc., I'll check it they are the same all the time. Anyway, the above
> printk strings aren't present in dmesg after a successful resume even,
> so I must be doing something wrong...
These printks of mine are clearly out of scope of dmesg, because they
don't happen in the context of the resumed system. I think I'm starting
to understand...
>>> 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.
Looks like this was the effect of portport_pc being loaded when I run
s2disk from the desktop, but not when I started it after init=/bin/bash.
--
Regards,
Feri.
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