Re: Linux 4.15-rc2: Regression in resume from ACPI S3

[Maarten Lankhorst <dev@mblankhorst.nl>]

Op 14-12-17 om 16:54 schreef Rafael J. Wysocki:
> On Thursday, December 14, 2017 4:52:22 PM CET Thomas Gleixner wrote:
>> On Thu, 14 Dec 2017, Rafael J. Wysocki wrote:
>>> The problem here is that pci_pm_thaw_noirq() calls pci_restore_state() which
>>> in fact requires the device to be in D0, so the caller should put it into
>>> D0 instead of trying to "update" its power state.
>>>
>>> [Note that the PCI layer doesn't put devices into low-power states during the
>>> hibernation's "freeze" transition, but drivers can legitimately do that in
>>> their "freeze" callbacks which was overlooked in that code and that's what
>>> i915 does.]
>>>
>>> So IMO what we need is the change below.  I'm going to test it shortly,
>>> but please give it a go too.
>> So now this looks more reasonable:
>>
>>   irq_migrate_all_off_this_cpu: Mask 125 pci_msi_mask_irq+0x0/0x10
>>   __pci_write_msi_msg: 0000:00:02.0 00000000fee0100c 0000412a 
>>   __pci_write_msi_msg: Not written
>>   ...
>>   device_pm_callback_start: i915 0000:00:02.0, parent: pci0000:00, noirq bus [thaw]
>>   pci_pm_thaw_noirq <-dpm_run_callback
>>   __pci_write_msi_msg: 0000:00:02.0 00000000fee0100c 0000412a 
>>   device_pm_callback_end: i915 0000:00:02.0, err=0
>>   ...
>>   resume_irqs: Resume 125
>>   ...
>>   irq_handler_entry: irq=125 name=i915
> Cool.
>
> Let me respin it with a changelog etc then.
>
> Thanks,
> Rafael
>
>
The machine I was using for reproducing the bug appears to be fixed with this patch, so I now sent
it to intel's trybot for results.

https://patchwork.freedesktop.org/series/35367/

Thanks for looking at the bug!

~Maarten