From 15a5b25408538172bd1dafae373c729a82a1e86d Mon Sep 17 00:00:00 2001 From: Ani Sinha Date: Fri, 18 Sep 2020 14:11:03 +0530 Subject: [PATCH] i440fx/acpi: do not add hotplug related amls for cold plugged bridges 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 Suggested-by: Julia Suvorova Reviewed-by: Julia Suvorova Reviewed-by: Igor Mammedov Message-Id: <20200918084111.15339-6-ani@anisinha.ca> Reviewed-by: Michael S. Tsirkin Signed-off-by: Michael S. Tsirkin --- hw/i386/acpi-build.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index b49d360ab2..2b17843837 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -365,6 +365,7 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, int slot = PCI_SLOT(i); bool hotplug_enabled_dev; bool bridge_in_acpi; + bool cold_plugged_bridge; if (!pdev) { if (bsel) { /* add hotplug slots for non present devices */ @@ -386,15 +387,14 @@ static void build_append_pci_bus_devices(Aml *parent_scope, PCIBus *bus, pc = PCI_DEVICE_GET_CLASS(pdev); dc = DEVICE_GET_CLASS(pdev); - /* When hotplug for bridges is enabled, bridges are - * described in ACPI separately (see build_pci_bus_end). - * In this case they aren't themselves hot-pluggable. + /* + * Cold plugged bridges aren't themselves hot-pluggable. * Hotplugged bridges *are* hot-pluggable. */ - bridge_in_acpi = pc->is_bridge && pcihp_bridge_en && - !DEVICE(pdev)->hotplugged; + cold_plugged_bridge = pc->is_bridge && !DEVICE(pdev)->hotplugged; + bridge_in_acpi = cold_plugged_bridge && pcihp_bridge_en; - hotplug_enabled_dev = bsel && dc->hotpluggable && !bridge_in_acpi; + hotplug_enabled_dev = bsel && dc->hotpluggable && !cold_plugged_bridge; if (pc->class_id == PCI_CLASS_BRIDGE_ISA) { continue;