Re: Side note on Shuttle XPC / AMD X2 (SN95G5V3) (Re: [PATCH] nve(4) locking cleanup)

Matthew Dillon wrote:
> :I found someone. :)  They don't have an X2 processor, just a 6400, and it does 
> :seem that the MP Table in there case does have some busted entries.  However, 
> :the link devices used for APIC routing do work ok so with ACPI enabled 6.0 
> :booted up ok out of the box with APIC enabled.  Probably they (Shuttle) got 
> :by with a busted MP Table because Windows probably just uses ACPI and worked 
> :fine out of the box.
> :
> :-- 
> :John Baldwin <jhb_at_FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
> 
>     Buy an AMD Athlon X2 for that person so you can get SMP working, and
>     see if you hit the IRQ 7 problem.  If the system has to reroute anything
>     through the 8259 (e.g. like the clock interrupt), you will probably
>     see spurious irq 7's.  If it disables the 8259 entirely it should be ok.
>     I suspect that if the ACPI link entries are good, that will be the 
>     only problem you face getting SMP working.
> 

Luckily, we no longer have to worry about routing the 8254 through the
AT-PIC anymore in FreeBSD.  More and more chipsets and motherboards are
axeing the logic to make this work, and it's a loosing battle to keep
on trying to work around it.  It wouldn't be too surprising if the
8259 goes away entirely in the next 2-3 years on Athlon and Opteron
designs.

>     Note that I did a followup commit to the one I posted to clean
>     up my programming option for the hypertransport configuration.  The
>     one I posted was just an initial workaround.  Look at the CVS logs
>     for more info.  Those configuration registers are insane and the
>     Shuttle BIOS clearly misprogrammed the one I was finally able to
>     track down.
> 
>     I intend to implement the link entry stuff for DragonFly after our
>     next release.  For this release we already have too many feature items
>     and not enough time to stabilize yet another one... so that will be 
>     post-release work.
> 
>     I have to say that the new Shuttle XPC populated with an Athlon X2
>     is a really nifty machine.  It's ultra fast, SMP, yet much, much quieter
>     then older slower shuttles.  It runs nice and cool.  It is clearly a 
>     bug winner for Shuttle and AMD.

It does look nice.

Scott