ACPI: Do not export hid/modalias sysfs file for ACPI objects without a HID

Boot and compile tested.
The fact that pnp.ids can now be empty needs testing on some
further machines, though.

This should handle a "modprobe is wrongly called by udev" issue:
https://bugzilla.kernel.org/show_bug.cgi?id=19162

Modaliase files in
/sys/devices/LNXSYSTM:00/
went down from 113 to 71 on my tested system.

This is a sysfs change, but userspace must already be able to handle it.

Also do not fill up pnp.ids list with a "struct hid"
entry. This comment:
     * This generic ID isn't useful for driver binding, but it provides
     * the useful property that "every acpi_device has an ID."
is still half way true:
Best you never touch pnp.ids list directly or make sure it can be empty,
instead use:
char *acpi_device_hid()
which always returns a value ("device" as a dummy if the object
has no hid).

Signed-off-by: Thomas Renninger <trenn@suse.de>
CC: Zhang Rui <rui.zhang@intel.com>
CC: kay.sievers@vrfy.org
CC: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This commit is contained in:
Thomas Renninger 2010-10-01 10:53:59 +02:00 committed by Len Brown
parent 899611ee7d
commit 2b2ae7c7f8

View file

@ -26,6 +26,9 @@ extern struct acpi_device *acpi_root;
#define ACPI_IS_ROOT_DEVICE(device) (!(device)->parent)
/* Should be const */
static char* dummy_hid = "device";
static LIST_HEAD(acpi_device_list);
static LIST_HEAD(acpi_bus_id_list);
DEFINE_MUTEX(acpi_device_lock);
@ -49,6 +52,9 @@ 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 +208,15 @@ 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 +324,9 @@ 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],
@ -1014,6 +1025,9 @@ 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 +1156,6 @@ 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)