[6/6] acpi: parallel: don't use _STA method
diff mbox series

Message ID 20200327121111.1530-7-kraxel@redhat.com
State New
Headers show
Series
  • acpi: i386 tweaks
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Commit Message

Gerd Hoffmann March 27, 2020, 12:11 p.m. UTC
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 <kraxel@redhat.com>
---
 hw/i386/acpi-build-pc.c | 29 ++++++++---------------------
 1 file changed, 8 insertions(+), 21 deletions(-)

Comments

Igor Mammedov March 27, 2020, 2:35 p.m. UTC | #1
On Fri, 27 Mar 2020 13:11:11 +0100
Gerd Hoffmann <kraxel@redhat.com> wrote:

> 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 <kraxel@redhat.com>
> ---
>  hw/i386/acpi-build-pc.c | 29 ++++++++---------------------
>  1 file changed, 8 insertions(+), 21 deletions(-)
> 
> diff --git a/hw/i386/acpi-build-pc.c b/hw/i386/acpi-build-pc.c
> index 97af5eac3d79..8bab105d5e44 100644
> --- a/hw/i386/acpi-build-pc.c
> +++ b/hw/i386/acpi-build-pc.c
> @@ -1169,39 +1169,26 @@ 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)) {
same comment as in 5/6 applies here

> +        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_com_device_aml(Aml *scope, uint8_t uid)
> @@ -1248,7 +1235,7 @@ 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);
>      build_com_device_aml(scope, 1);
>      build_com_device_aml(scope, 2);
>

Patch
diff mbox series

diff --git a/hw/i386/acpi-build-pc.c b/hw/i386/acpi-build-pc.c
index 97af5eac3d79..8bab105d5e44 100644
--- a/hw/i386/acpi-build-pc.c
+++ b/hw/i386/acpi-build-pc.c
@@ -1169,39 +1169,26 @@  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_com_device_aml(Aml *scope, uint8_t uid)
@@ -1248,7 +1235,7 @@  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);
     build_com_device_aml(scope, 1);
     build_com_device_aml(scope, 2);