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path: root/drivers/acpi/scan.c
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Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c37
1 files changed, 20 insertions, 17 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index f87f04603b6..2b6c21d86b9 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -26,6 +26,8 @@ extern struct acpi_device *acpi_root;
#define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent)
+static const char *dummy_hid = "device";
+
static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_MUTEX(acpi_device_lock);
@@ -49,6 +51,9 @@ static int create_modalias(struct acpi_device *acpi_dev, char *modalias,
int count;
struct acpi_hardware_id *id;
+ if (list_empty(&acpi_dev->pnp.ids))
+ return 0;
+
len = snprintf(modalias, size, "acpi:");
size -= len;
@@ -202,13 +207,15 @@ static int acpi_device_setup_files(struct acpi_device *dev)
goto end;
}
- result = device_create_file(&dev->dev, &dev_attr_hid);
- if (result)
- goto end;
+ if (!list_empty(&dev->pnp.ids)) {
+ result = device_create_file(&dev->dev, &dev_attr_hid);
+ if (result)
+ goto end;
- result = device_create_file(&dev->dev, &dev_attr_modalias);
- if (result)
- goto end;
+ result = device_create_file(&dev->dev, &dev_attr_modalias);
+ if (result)
+ goto end;
+ }
/*
* If device has _EJ0, 'eject' file is created that is used to trigger
@@ -316,6 +323,9 @@ static int acpi_device_uevent(struct device *dev, struct kobj_uevent_env *env)
struct acpi_device *acpi_dev = to_acpi_device(dev);
int len;
+ if (list_empty(&acpi_dev->pnp.ids))
+ return 0;
+
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
len = create_modalias(acpi_dev, &env->buf[env->buflen - 1],
@@ -1010,10 +1020,13 @@ static int acpi_dock_match(struct acpi_device *device)
return acpi_get_handle(device->handle, "_DCK", &tmp);
}
-char *acpi_device_hid(struct acpi_device *device)
+const char *acpi_device_hid(struct acpi_device *device)
{
struct acpi_hardware_id *hid;
+ if (list_empty(&device->pnp.ids))
+ return dummy_hid;
+
hid = list_first_entry(&device->pnp.ids, struct acpi_hardware_id, list);
return hid->id;
}
@@ -1142,16 +1155,6 @@ static void acpi_device_set_id(struct acpi_device *device)
acpi_add_id(device, ACPI_BUTTON_HID_SLEEPF);
break;
}
-
- /*
- * We build acpi_devices for some objects that don't have _HID or _CID,
- * e.g., PCI bridges and slots. Drivers can't bind to these objects,
- * but we do use them indirectly by traversing the acpi_device tree.
- * This generic ID isn't useful for driver binding, but it provides
- * the useful property that "every acpi_device has an ID."
- */
- if (list_empty(&device->pnp.ids))
- acpi_add_id(device, "device");
}
static int acpi_device_set_context(struct acpi_device *device)