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

From: Rafael J. Wysocki
Date: Fri Jan 10 2014 - 20:07:39 EST


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@xxxxxxxxxxxxxxx>

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.
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