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 <address@hidden>
Reviewed-by: Igor Mammedov <address@hidden>
---
hw/i386/acpi-build.c | 32 ++++++++------------------------
1 file changed, 8 insertions(+), 24 deletions(-)
diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
index f79e5eaf170d..a99e5bbd1156 100644
--- a/hw/i386/acpi-build.c
+++ b/hw/i386/acpi-build.c
@@ -1202,50 +1202,34 @@ static Aml *build_lpt_device_aml(void)
return dev;
}
-static Aml *build_com_device_aml(uint8_t uid)
+static void build_com_device_aml(Aml *scope, uint8_t uid)
{
Aml *dev;
Aml *crs;
- Aml *method;
- Aml *if_ctx;
- Aml *else_ctx;
- Aml *zero = aml_int(0);
- Aml *is_present = aml_local(0);
- const char *enabled_field = "CAEN";
uint8_t irq = 4;
uint16_t io_port = 0x03F8;
assert(uid == 1 || uid == 2);
if (uid == 2) {
- enabled_field = "CBEN";
irq = 3;
io_port = 0x02F8;
}
+ if (!memory_region_present(get_system_io(), io_port)) {
+ return;
+ }
dev = aml_device("COM%d", uid);
aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0501")));
aml_append(dev, aml_name_decl("_UID", aml_int(uid)));
- method = aml_method("_STA", 0, AML_NOTSERIALIZED);
- aml_append(method, aml_store(aml_name("%s", enabled_field), 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, io_port, io_port, 0x00, 0x08));
aml_append(crs, aml_irq_no_flags(irq));
aml_append(dev, aml_name_decl("_CRS", crs));
- return dev;
+ aml_append(scope, dev);
}
static void build_isa_devices_aml(Aml *table)
@@ -1262,8 +1246,8 @@ static void build_isa_devices_aml(Aml *table)
aml_append(scope, build_fdc_device_aml(fdc));
}
aml_append(scope, build_lpt_device_aml());
- aml_append(scope, build_com_device_aml(1));
- aml_append(scope, build_com_device_aml(2));
+ build_com_device_aml(scope, 1);
+ build_com_device_aml(scope, 2);
if (ambiguous) {
error_report("Multiple ISA busses, unable to define IPMI ACPI data");