ThinkPad: reboots after successful shutdown -p

[Warner Losh]

On Tue, Mar 16, 2021 at 10:18 PM Xin Li <delphij at freebsd.org> wrote:

> On 11/17/19 23:14, Xin Li wrote:
> > Hi,
> >
> > I recently noticed that if I do a 'shutdown -p' from -CURRENT, the
> > system would shut down and seemingly powered off, then it would restart
> > after about 5-10 seconds.
> >
> > Is this a known issue?  Arguably this is not necessarily a FreeBSD
> > issue, but it seems that the Windows 10 installation doesn't have the
> > problem, so I guess there might be some difference between our and
> > Windows's shutdown sequence.
>
> I've found a workaround for this, for the record, setting
> hw.efi.poweroff=0 would make the laptop to correctly shutdown.
>
> However I don't see anything wrong with sys/dev/efidev/efirt.c's
> implementation of EFI shutdown; it appears to be essentially the same as
> implemented in command_poweroff() in stand/efi/loader/main.c, but
> 'poweroff' would work just fine in loader.efi.
>
> Can someone familiar with the code shed me some light here? :-)
>
> It looks like what Linux did was to prefer ACPI S5, unless it's not
> available or the system have HW_REDUCED flag in FADT, so if we do
> something similar it would fix the issue for me, but according to
> bugs.freebsd.org/233998 that's not the case for at least Conor's system
> (_S5 appears to be in the ACPI dump), so I think it's something else...
>

For me, interrupt storm on shutdown has been the causes of issues like
this...

Any chance you can eliminate that as a possibility?

Warner