Re: [Qemu-devel] [PATCH 09/11] ACPI: move PRST OperationRegion into SSDT

[Igor Mammedov]

On Mon, 16 Dec 2013 22:13:30 +0100
Laszlo Ersek <address@hidden> wrote:

> On 12/16/13 21:38, Igor Mammedov wrote:
> > On Mon, 16 Dec 2013 21:30:14 +0200
> > "Michael S. Tsirkin" <address@hidden> wrote:
> > 
> >> On Fri, Dec 13, 2013 at 05:22:14PM +0100, Igor Mammedov wrote:
> >>> .. and report range used by it to OSPM via _CRS.
> >>> PRST is needed in SSDT since its base will depend on
> >>> chipset and will be dynamically set by QEMU.
> >>> Also move PRSC() method along with PRST since cross
> >>> table reference to PRST doesn't work.
> >>
> >> Could you clarify this last sentence?
> >> I don't mind where it is but I'd like to know
> >> where does the limitation come from.
> > It's empiric deduction so far I haven't found such limitation in spec yet.
> > iasl builds tables just fine but neither linux nor windows were able to find
> > Operation region from SSDT when loading DSDT, failing whole table loading
> > process. Decompiling DSDT/SSDT tables in guest shows that region is in
> > expected scope but OSPM refuses to see it when referenced outside SSDT.
> 
> There seem to be four things here:
> - the OperationRegion definition,
> - its external declaration,
> - the Field() declaration,
> - use of fields.
> 
> I think referencing an OperationRegion defined in another table should
> work (by way of External). I suspect the tricky part is with Field():
                  ^^^ it looks like it should work and decompiled tables
look fine as well but it unfortunately doesn't.

> 
>     The fields are parts of the object named by RegionName, but their
>     names appear in the same scope as the Field term.
> 
> So,
> - maybe moving PRST only, and leaving the definition of PRS (as part of
> Field()) together with PRSC would suffice,
That was the first thing I've tried.

> - or, after moving the definition of PRS (as part of Field()) together
> with PRST to another table, all references to PRS (in the PRSC method)
> would have to be qualified. (But I guess this is what you tried.)
yep, that didn't work too.

I'm not fun of moving a bunch of code around, but looks like there is
no other way. I'd be happy to try if there are any other suggestions.

> 
> Laszlo
> 


-- 
Regards,
  Igor