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authorThomas Renninger <trenn@suse.de>2010-10-01 10:53:59 +0200
committerLen Brown <len.brown@intel.com>2010-10-01 15:36:39 -0400
commit2b2ae7c7f8e25043793042eb9df88aa875b4cff8 (patch)
tree83daed7afd0d0b060219f8aff97a645dbf8027bc /drivers/acpi/scan.c
parent899611ee7d373e5eeda08e9a8632684e1ebbbf00 (diff)
downloadlinux-linaro-android-2b2ae7c7f8e25043793042eb9df88aa875b4cff8.tar.gz
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>
Diffstat (limited to 'drivers/acpi/scan.c')
-rw-r--r--drivers/acpi/scan.c36
1 files changed, 20 insertions, 16 deletions
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c
index b23825ecfa3..81aec8d66fd 100644
--- a/drivers/acpi/scan.c
+++ b/drivers/acpi/scan.c
@@ -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)