Re: [PATCH v5 13/15] acpi: drop build_piix4_pm()

[Igor Mammedov <imammedo@redhat.com>]

On Tue, 12 May 2020 13:16:05 +0200
Gerd Hoffmann <kraxel@redhat.com> wrote:

> On Mon, May 11, 2020 at 09:37:32PM +0200, Igor Mammedov wrote:
> > On Thu,  7 May 2020 15:16:38 +0200
> > Gerd Hoffmann <kraxel@redhat.com> wrote:
> >   
> > > The _SB.PCI0.PX13.P13C opregion (holds isa device enable bits)
> > > is not used any more, remove it from DSDT.
> > > 
> > > Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
> > > ---
> > >  hw/i386/acpi-build.c | 16 ----------------
> > >  1 file changed, 16 deletions(-)
> > > 
> > > diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> > > index 765409a90eb6..c1e63cce5e8e 100644
> > > --- a/hw/i386/acpi-build.c
> > > +++ b/hw/i386/acpi-build.c
> > > @@ -1441,21 +1441,6 @@ static void build_q35_isa_bridge(Aml *table)
> > >      aml_append(table, scope);
> > >  }
> > >  
> > > -static void build_piix4_pm(Aml *table)
> > > -{
> > > -    Aml *dev;
> > > -    Aml *scope;
> > > -
> > > -    scope =  aml_scope("_SB.PCI0");
> > > -    dev = aml_device("PX13");
> > > -    aml_append(dev, aml_name_decl("_ADR", aml_int(0x00010003)));  
> > I agree about removing P13C but I'm not sure if it's safe to remove
> > whole isa bridge  
> 
> The isa bridge is _SB0.PCI0.ISA (piix4 function 0).
> _SB.PCI0.PX13 is the acpi pm device (piix4 function 3).
> 
> So this does _not_ remove the isa bridge.  And given that PX13 has
> nothing declared beside the opregion we are removing and I have not
> found any other references to the PX13 device I assumed it is ok to drop
> that one too.  Didn't notice any odd side effects in testing.
I don't see HID or some other way to tell guest that it should load a driver
for it so probably we can remove it.
If it breaks some legacy OS we can always add it back.


> 
> take care,
>   Gerd
>