Panic on suspend

[Nate Lawson]

Filippo Forti wrote:
> I got a fully reproduceable panic while trying to suspend (to S3) on my laptop.
> FreeBSD is -CURRENT from Monday.
> 
> I'm using a modified DSDT which used to work before I updated on Monday.
> dmesg from after reboot is attacched.
> 
> Here comes gbd output
> 
> Fatal trap 12: page fault while in vm86 mode
> fault virtual address	= 0x2000
> fault code				= user write, page not present
> instruction pointer		= 0xc000:0x5195
                                   ^^^^^^^

That is in the VGA BIOS.  Try setting this sysctl before suspending:

hw.acpi.reset_video=0

> stack pointer			= 0x0:0xfe4
> frame pointer			= 0x0:0x0
> code segment			= base 0x600005, limit 0x2, type 0x11
> 						= DPL 1, pres 0, def32 0, gran 0
> processor eflag			= interrupt enabled, resume, mv86, IOPL = 0
> current process 		= 1046 (acpiconf)
> [thread pid 1046 tid 100084]
> Stopped at 0x5159: *** error reading from address 5159 ***

Ian committed code to restore the VESA state so we shouldn't reset video 
redundantly.  I'm thinking of changing the default to 0 in -current.

-- 
Nate