Re: [Qemu-devel] [PATCH v7 1/3] i386/acpi: make floppy controller object dynamic

[Marcel Apfelbaum <marcel.apfelbaum@gmail.com>]

On 01/26/2016 03:50 PM, Igor Mammedov wrote:
> From: Roman Kagan <rkagan@virtuozzo.com>
>
> Instead of statically declaring the floppy controller in DSDT, with its
> _STA method depending on some obscure bit in the parent ISA bridge, add
> the object dynamically to DSDT via AML API only when the controller is
> present.
>
> The _STA method is no longer necessary and is therefore dropped.  So are
> the declarations of the fields indicating whether the contoller is
> enabled.
>
> Signed-off-by: Roman Kagan <rkagan@virtuozzo.com>
> Signed-off-by: Igor Mammedov <imammedo@redhat.com>
> ---
>   hw/i386/acpi-build.c | 27 +++------------------------
>   1 file changed, 3 insertions(+), 24 deletions(-)
>
> diff --git a/hw/i386/acpi-build.c b/hw/i386/acpi-build.c
> index 78758e2..2f685fb 100644
> --- a/hw/i386/acpi-build.c
> +++ b/hw/i386/acpi-build.c
> @@ -1231,29 +1231,10 @@ static Aml *build_fdc_device_aml(void)
>   {
>       Aml *dev;
>       Aml *crs;
> -    Aml *method;
> -    Aml *if_ctx;
> -    Aml *else_ctx;
> -    Aml *zero = aml_int(0);
> -    Aml *is_present = aml_local(0);
>
>       dev = aml_device("FDC0");
>       aml_append(dev, aml_name_decl("_HID", aml_eisaid("PNP0700")));
>
> -    method = aml_method("_STA", 0, AML_NOTSERIALIZED);
> -    aml_append(method, aml_store(aml_name("FDEN"), 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);
> -
>       crs = aml_resource_template();
>       aml_append(crs, aml_io(AML_DECODE16, 0x03F2, 0x03F2, 0x00, 0x04));
>       aml_append(crs, aml_io(AML_DECODE16, 0x03F7, 0x03F7, 0x00, 0x01));
> @@ -1411,7 +1392,9 @@ static void build_isa_devices_aml(Aml *table)
>       aml_append(scope, build_rtc_device_aml());
>       aml_append(scope, build_kbd_device_aml());
>       aml_append(scope, build_mouse_device_aml());
> -    aml_append(scope, build_fdc_device_aml());
> +    if (!!pc_find_fdc0()) {

You don't really need the double negation, right?
Anyway, I agree with the patch.

Reviewed-by: Marcel Apfelbaum <marcel@redhat.com>

Thanks,
Marcel

> +        aml_append(scope, build_fdc_device_aml());
> +    }
>       aml_append(scope, build_lpt_device_aml());
>       aml_append(scope, build_com_device_aml(1));
>       aml_append(scope, build_com_device_aml(2));
> @@ -1780,8 +1763,6 @@ static void build_q35_isa_bridge(Aml *table)
>       aml_append(field, aml_named_field("COMB", 3));
>       aml_append(field, aml_reserved_field(1));
>       aml_append(field, aml_named_field("LPTD", 2));
> -    aml_append(field, aml_reserved_field(2));
> -    aml_append(field, aml_named_field("FDCD", 2));
>       aml_append(dev, field);
>
>       aml_append(dev, aml_operation_region("LPCE", AML_PCI_CONFIG,
> @@ -1791,7 +1772,6 @@ static void build_q35_isa_bridge(Aml *table)
>       aml_append(field, aml_named_field("CAEN", 1));
>       aml_append(field, aml_named_field("CBEN", 1));
>       aml_append(field, aml_named_field("LPEN", 1));
> -    aml_append(field, aml_named_field("FDEN", 1));
>       aml_append(dev, field);
>
>       aml_append(scope, dev);
> @@ -1839,7 +1819,6 @@ static void build_piix4_isa_bridge(Aml *table)
>       aml_append(field, aml_reserved_field(3));
>       aml_append(field, aml_named_field("CBEN", 1));
>       aml_append(dev, field);
> -    aml_append(dev, aml_name_decl("FDEN", aml_int(1)));
>
>       aml_append(scope, dev);
>       aml_append(table, scope);
>