From: Gerd Hoffmann <kra...@redhat.com> The _STA method dates back to the days where we had a static DSDT. The device is listed in the DSDT table unconditionally and the _STA method checks a bit in the isa bridge pci config space to figure whenever a given is isa device is present or not, then evaluates to 0x0f (present) or 0x00 (absent).
These days the DSDT is generated by qemu anyway, so if a device is not present we can simply drop it from the DSDT instead. Signed-off-by: Gerd Hoffmann <kra...@redhat.com> Reviewed-by: Igor Mammedov <imamm...@redhat.com> Message-Id: <20200515150421.25479-7-kra...@redhat.com> --- hw/i386/acpi-build.c | 29 ++++++++--------------------- 1 file changed, 8 insertions(+), 21 deletions(-) diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c index 6de25f6484..2cafad03e2 100644 --- a/hw/i386/acpi-build.c +++ b/hw/i386/acpi-build.c @@ -1173,39 +1173,26 @@ static Aml *build_mouse_device_aml(void) return dev; } -static Aml *build_lpt_device_aml(void) +static void build_lpt_device_aml(Aml *scope) { Aml *dev; Aml *crs; - Aml *method; - Aml *if_ctx; - Aml *else_ctx; - Aml *zero = aml_int(0); - Aml *is_present = aml_local(0); + + if (!memory_region_present(get_system_io(), 0x0378)) { + return; + } dev = aml_device("LPT"); aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0400"))); - method = aml_method("_STA", 0, AML_NOTSERIALIZED); - aml_append(method, aml_store(aml_name("LPEN"), is_present)); - if_ctx = aml_if(aml_equal(is_present, zero)); - { - aml_append(if_ctx, aml_return(aml_int(0x00))); - } - aml_append(method, if_ctx); - else_ctx = aml_else(); - { - aml_append(else_ctx, aml_return(aml_int(0x0f))); - } - aml_append(method, else_ctx); - aml_append(dev, method); + aml_append(dev, aml_name_decl("_STA", aml_int(0xf))); crs = aml_resource_template(); aml_append(crs, aml_io(AML_DECODE16, 0x0378, 0x0378, 0x08, 0x08)); aml_append(crs, aml_irq_no_flags(7)); aml_append(dev, aml_name_decl("_CRS", crs)); - return dev; + aml_append(scope, dev); } static void build_isa_devices_aml(Aml *table) @@ -1221,7 +1208,7 @@ static void build_isa_devices_aml(Aml *table) if (fdc) { aml_append(scope, build_fdc_device_aml(fdc)); } - aml_append(scope, build_lpt_device_aml()); + build_lpt_device_aml(scope); if (ambiguous) { error_report("Multiple ISA busses, unable to define IPMI ACPI data"); -- MST