system sporadically hangs on shutdown after switching to WITH_NEW_XORG

[Javad Kouhi]

On Wed, 19 Jun 2013 01:58:18 +0430, Jeremy Chadwick <jdc at koitsu.org> wrote:

> On Wed, Jun 19, 2013 at 01:41:10AM +0430, Javad Kouhi wrote:
>> I've read the posts again. Although the issue looks same as Michiel
>> Boland (first link) but I'm not sure if the root of the issue is same
>> as Michiel's too (second link). Anyway, it should be discussed in
>> another thread as you said.
>
> Let me be more clear:
>
> I have seen repeated reports from people complaining about "lockups when
> shutting down" many times over the years.  The ones I remember:
>
> - Certain oddities with SCSI/SATA storage drivers and disks (many of
>   these have been fixed)
> - ACPI-based reboot not working correctly on some motherboards
>   (depends on hw.acpi.handle_reboot and sometimes
>   hw.acpi.disable_on_reboot) -- not sure if this still pops up
> - USB layer causing issues, or possibly some USB CAM integration
>   problem (this is still an ongoing one)
> - Now some sort of weird Intel graphics driver (and DRM?) quirk
>   involving moused(8) and Vsync (the issue reported by Michiel)
>
> And I'm certain I'm forgetting others.
>
> What Kevin Oberman said also applies -- these are painful to debug
> because the system is already in a "shutting down" state where usability
> and accessibility becomes bare minimal, and you're kind of at your
> wits end.
>
> Booting verbose can help -- there are other messages printed to the VGA
> (and/or serial) console during the shutdown phase when verbose.
>
> All you can hope for is that the kernel is still alive and Ctrl-Alt-Esc
> to force a drop to DDB (assuming all of this is enabled in your kernel)
> works and that someone familiar with the FreeBSD kernel can help you
> debug it (possibly it's just easier to do that, type "panic", then
> issue "call doadump" to force a dump to swap at that point -- kib@
> might have better recommendations).
>
> Serial console can also greatly help, because quite often there are
> pages upon pages of debugging information that are useful, otherwise you
> have to hope the VGA console keyboard is functional (even more tricky
> with USB) and that Scroll Lock + Page Up/Down function along with taking
> photos of the screen; doing it this way is stressful and painful for
> everyone involved.
>
> I hope this sheds some light on why I said what I did.  :-)
>


Ok, I will compile a new kernel with DDB option. I will submit the crash  
info and dmesg output the next time it happens. (in a new thread)

Thanks for your help.

Regards,