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acpi: x86: remove _ADR on host bridges
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ACPI spec (since 2.0a) says
"
A device object must contain either an _HID object or
an _ADR object, but can contain both.
"

_ADR is used when device is attached to an ennumerable bus,
however hostbridge is not and uses dedicated _HID for
discovery, drop _ADR field.

It doesn't seem that having _ADR has a negative effects
OSes manage to tolerate that, but there is no point of
having it there. (only pc/q35 has it hostbridge description,
while others (microvm/arm) don't)

Signed-off-by: Igor Mammedov <imammedo@redhat.com>
Message-Id: <20230720133858.1974024-6-imammedo@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
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Igor Mammedov authored and mstsirkin committed Aug 3, 2023
1 parent d3dc64f commit 5ce869f
Showing 1 changed file with 0 additions and 3 deletions.
3 changes: 0 additions & 3 deletions hw/i386/acpi-build.c
Original file line number Diff line number Diff line change
Expand Up @@ -1464,7 +1464,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
sb_scope = aml_scope("_SB");
dev = aml_device("PCI0");
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
aml_append(dev, aml_pci_edsm());
aml_append(sb_scope, dev);
Expand All @@ -1479,7 +1478,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
dev = aml_device("PCI0");
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
aml_append(dev, aml_name_decl("_CID", aml_eisaid("PNP0A03")));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
aml_append(dev, aml_name_decl("_UID", aml_int(pcmc->pci_root_uid)));
aml_append(dev, build_q35_osc_method(!pm->pcihp_bridge_en));
aml_append(dev, aml_pci_edsm());
Expand Down Expand Up @@ -1593,7 +1591,6 @@ build_dsdt(GArray *table_data, BIOSLinker *linker,
aml_append(pkg, aml_eisaid("PNP0A08"));
aml_append(pkg, aml_eisaid("PNP0A03"));
aml_append(dev, aml_name_decl("_CID", pkg));
aml_append(dev, aml_name_decl("_ADR", aml_int(0)));
build_cxl_osc_method(dev);
} else if (pci_bus_is_express(bus)) {
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0A08")));
Expand Down

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