Re: [PATCH] ACPI/SCAN: _STA status read

["Rafael J. Wysocki" <rjw@rjwysocki.net>]

On Friday, January 10, 2014 04:00:05 PM Srinivas Pandruvada wrote:
> This patch adds a "status" attribute for an acpi device. This status
> attribute shows the value of _STA object. The _STA object returns
> current status of an ACPI device to show enabled, disabled or removed.
> 
> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>

Queued up for 3.14, thanks!

> ---
>  drivers/acpi/scan.c | 22 ++++++++++++++++++++++
>  1 file changed, 22 insertions(+)
> 
> diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
> index fd39459..a5f4a60 100644
> --- a/drivers/acpi/scan.c
> +++ b/drivers/acpi/scan.c
> @@ -567,6 +567,20 @@ acpi_device_sun_show(struct device *dev, struct device_attribute *attr,
>  }
>  static DEVICE_ATTR(sun, 0444, acpi_device_sun_show, NULL);
>  
> +static ssize_t status_show(struct device *dev, struct device_attribute *attr,
> +				char *buf) {
> +	struct acpi_device *acpi_dev = to_acpi_device(dev);
> +	acpi_status status;
> +	unsigned long long sta;
> +
> +	status = acpi_evaluate_integer(acpi_dev->handle, "_STA", NULL, &sta);
> +	if (ACPI_FAILURE(status))
> +		return -ENODEV;
> +
> +	return sprintf(buf, "%llu\n", sta);
> +}
> +static DEVICE_ATTR_RO(status);
> +
>  static int acpi_device_setup_files(struct acpi_device *dev)
>  {
>  	struct acpi_buffer buffer = {ACPI_ALLOCATE_BUFFER, NULL};
> @@ -622,6 +636,12 @@ static int acpi_device_setup_files(struct acpi_device *dev)
>  		dev->pnp.sun = (unsigned long)-1;
>  	}
>  
> +	if (acpi_has_method(dev->handle, "_STA")) {
> +		result = device_create_file(&dev->dev, &dev_attr_status);
> +		if (result)
> +			goto end;
> +	}
> +
>          /*
>           * If device has _EJ0, 'eject' file is created that is used to trigger
>           * hot-removal function from userland.
> @@ -677,6 +697,8 @@ static void acpi_device_remove_files(struct acpi_device *dev)
>  		device_remove_file(&dev->dev, &dev_attr_adr);
>  	device_remove_file(&dev->dev, &dev_attr_modalias);
>  	device_remove_file(&dev->dev, &dev_attr_hid);
> +	if (acpi_has_method(dev->handle, "_STA"))
> +		device_remove_file(&dev->dev, &dev_attr_status);
>  	if (dev->handle)
>  		device_remove_file(&dev->dev, &dev_attr_path);
>  }
> 

-- 
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.