Re: [PATCH v2 6/8] PCI: acpiphp: workaround for Thunderbolt on Acer Aspire S5

From: Rafael J. Wysocki
Date: Wed Jul 03 2013 - 17:49:16 EST


On Wednesday, July 03, 2013 03:45:50 PM Bjorn Helgaas wrote:
> On Wed, Jul 3, 2013 at 8:04 AM, Mika Westerberg
> <mika.westerberg@xxxxxxxxxxxxxxx> wrote:
> > From: "Kirill A. Shutemov" <kirill.shutemov@xxxxxxxxxxxxxxx>
> >
> > Correct ACPI PCI hotplug imeplementation should have _RMV method in a
> > PCI slot (device under pci bridge). In Acer Aspire S5 case we have it
> > deeper in hierarchy:
> >
> > Device (RP05)
> > {
> > // ...
> > Device (HRUP)
> > {
> > // ...
> > Device (HRDN)
> > {
> > // ...
> > Device (EPUP)
> > {
> > // ...
> > Method (_RMV, 0, NotSerialized) // _RMV: Removal Status
> > {
> > Return (One)
> > }
> > }
> > }
> > }
> > }
> >
> > Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> > Signed-off-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
> > ---
> > drivers/pci/hotplug/acpi_pcihp.c | 13 +++++++++++++
> > 1 file changed, 13 insertions(+)
> >
> > diff --git a/drivers/pci/hotplug/acpi_pcihp.c b/drivers/pci/hotplug/acpi_pcihp.c
> > index 2a47e82..d92ebfb 100644
> > --- a/drivers/pci/hotplug/acpi_pcihp.c
> > +++ b/drivers/pci/hotplug/acpi_pcihp.c
> > @@ -422,6 +422,19 @@ static int pcihp_is_ejectable(acpi_handle handle)
> > status = acpi_evaluate_integer(handle, "_RMV", NULL, &removable);
> > if (ACPI_SUCCESS(status) && removable)
> > return 1;
> > +
> > + /*
> > + * Workaround for Thunderbolt implementation on Acer Aspire S5.
> > + *
> > + * Correct ACPI PCI hotplug imeplementation has _RMV method in a PCI
> > + * slot (device under pci bridge). In Acer Aspire S5 case we have it
> > + * deeper in hierarchy.
>
> s/imeplementation/implementation/
>
> If you're casting aspersions on Acer for having an incorrect ACPI
> implementation, you should probably provide a spec reference. I think
> it's likely that the Acer implementation is actually correct per the
> spec, but Linux just isn't smart enough to handle it.

Agreed.

> > + */
> > + status = acpi_evaluate_integer(handle, "HRDN.EPUP._RMV", NULL,
> > + &removable);
> > + if (ACPI_SUCCESS(status) && removable)
> > + return 1;
> > +
> > return 0;
> > }
> >
> > --
> > 1.8.3.2
> >

--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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