Re: [Qemu-devel] [PATCH 1/2] ich9: update sci on gpe write

[Hu Tao <hutao@cn.fujitsu.com>]

On Thu, Sep 12, 2013 at 05:22:14PM +0200, Igor Mammedov wrote:
> On Wed, 21 Aug 2013 17:04:27 +0800
> Hu Tao <hutao@cn.fujitsu.com> wrote:
> 
> > OSPM may disable the sci by clearing GPEx_BLK EN bit, in the case
> > we have to set sci level to 0 or guest will receive sci interrupts
> > endlessly.
> 
> Could you make a more verbose comment, referring to relevant ACPI spec chapter
> and it would be nice,

See Section 5.6.4, ACPI 5.0, page 221.

>                       if you experienced problem with linux guest, to add
> symptoms here as well.

See http://lists.gnu.org/archive/html/qemu-devel/2012-12/msg02711.html.
I guess without this patch the same thing will happen in guest linux
when hotplugging a vcpu.

> 
> commit 633aa0ac did equivalent change to piix4 part, so it's worth to mention
> it here.
> 
> > Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
> > ---
> >  hw/acpi/ich9.c | 2 ++
> >  1 file changed, 2 insertions(+)
> > 
> > diff --git a/hw/acpi/ich9.c b/hw/acpi/ich9.c
> > index 3fb443d..8717c15 100644
> > --- a/hw/acpi/ich9.c
> > +++ b/hw/acpi/ich9.c
> > @@ -79,6 +79,8 @@ static void ich9_gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
> >  {
> >      ICH9LPCPMRegs *pm = opaque;
> >      acpi_gpe_ioport_writeb(&pm->acpi_regs, addr, val);
> > +
> > +    pm_update_sci(pm);
> >  }
> >  
> >  static const MemoryRegionOps ich9_gpe_ops = {