Re: Nobody cared about IRQs at shutdown

["Alexander E. Patrakov" <patrakov@gmail.com>]

01.12.2010 19:59, Alan Stern пишет:
> On Wed, 1 Dec 2010, Alexander E. Patrakov wrote:
>
>> Alan Stern wrote:
>>> On Tue, 30 Nov 2010, Alexander E. Patrakov wrote:
>>>
>>>> In fact, I think that there is something bad, not specific to USB,
>>>> FireWire or SATA. Without systemd, all those subsystems function
>>>> properly at shutdown. With systemd, it looks like there are many
>>>> mishandled interrupts (all of USB, FireWire and SATA) at shutdown.
>>>> What    could be this common thing? ACPI?
>>> I don't know -- what is systemd?
>> Systemd is a new init developed by Lennart Poettering. You can learn more at http://freedesktop.org/wiki/Software/systemd
>>
>> It employs high concurrency in starting and stopping services, starts many things on demand and thus boots faster than the traditional SysV init. And also exposes this bug :(
> All right.
>
> One last test.  What happens if you unbind the firewire driver and all
> the UHCI controllers except the one attached to IRQ 16?

As I was not sure if you mean 16 or 19, I did two tests. In both cases, 
the firewire driver and all UHCI controllers except one were unbound. In 
both cases, the system printed the line I added to uhci_hc_died(), 
reported a bad IRQ (16 and 19, respectively), waited, displayed SATA 
errors, waited again, and powered itself off. I.e., the screenshot is 
nearly identical to what I sent earlier.


> Possible explanations: IRQs are being misrouted, so the system thinks
> it gets IRQ 16 when in fact a different interrupt line was activated
> (this is related to ACPI, but I don't see any connection to systemd).
> Or the interrupt layer is malfunctioning and it thinks IRQs are
> arriving when they aren't.

I forgot to mention that only shutdown is problematic, reboots are OK.

-- 
Alexander E. Patrakov