Cold plugged bridges are not hot unpluggable, even when their hotplug
property (acpi-pci-hotplug-with-bridge-support) is turned off. Please see
the function acpi_pcihp_pc_no_hotplug(). However, with
the current implementaton, Windows would try to hot-unplug a pci bridge when
it's hotplug switch is off. This is regardless of whether there are devices
attached to the bridge. This is because we add ACPI code like _EJ0 etc for the
pci slot where the bridge is cold plugged.
In this fix, we identify a cold plugged bridge and for cold plugged bridges,
we do not add the appropriate ACPI methods that are used by the OS
to identify a hot-pluggable/unpluggable pci device. After this change, Windows
does not detect the cold plugged pci bridge as ejectable.
As a result of the patch, the following are the changes to the DSDT ACPI
table:
@@ -858,38 +858,33 @@
Return (Zero)
}
Method (_S2D, 0, NotSerialized) // _S2D: S2 Device State
{
Return (Zero)
}
Method (_S3D, 0, NotSerialized) // _S3D: S3 Device State
{
Return (Zero)
}
}
Device (S18)
{
- Name (_SUN, 0x03) // _SUN: Slot User Number
Name (_ADR, 0x00030000) // _ADR: Address
- Method (_EJ0, 1, NotSerialized) // _EJx: Eject Device
- {
- PCEJ (BSEL, _SUN)
- }
}
Device (S20)
{
Name (_SUN, 0x04) // _SUN: Slot User Number
Name (_ADR, 0x00040000) // _ADR: Address
Method (_EJ0, 1, NotSerialized) // _EJx: Eject Device
{
PCEJ (BSEL, _SUN)
}
}
Device (S28)
{
Name (_SUN, 0x05) // _SUN: Slot User Number
Name (_ADR, 0x00050000) // _ADR: Address
@@ -1148,37 +1143,32 @@
PCEJ (BSEL, _SUN)
}
}
Device (SF8)
{
Name (_SUN, 0x1F) // _SUN: Slot User Number
Name (_ADR, 0x001F0000) // _ADR: Address
Method (_EJ0, 1, NotSerialized) // _EJx: Eject Device
{
PCEJ (BSEL, _SUN)
}
}
Method (DVNT, 2, NotSerialized)
{
- If ((Arg0 & 0x08))
- {
- Notify (S18, Arg1)
- }
-
If ((Arg0 & 0x10))
{
Notify (S20, Arg1)
}
If ((Arg0 & 0x20))
{
Notify (S28, Arg1)
}
If ((Arg0 & 0x40))
{
Notify (S30, Arg1)
}
If ((Arg0 & 0x80))
While at it, I have also updated a stale comment.
Signed-off-by: Ani Sinha <ani@anisinha.ca>
Suggested-by: Julia Suvorova <jusual@redhat.com>
Reviewed-by: Julia Suvorova <jusual@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20200918084111.15339-6-ani@anisinha.ca>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
15a5b25408