From 2b2ae7c7f8e25043793042eb9df88aa875b4cff8 Mon Sep 17 00:00:00 2001 From: Thomas Renninger Date: Fri, 1 Oct 2010 10:53:59 +0200 Subject: [PATCH] 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 CC: Zhang Rui CC: kay.sievers@vrfy.org CC: Bjorn Helgaas Signed-off-by: Len Brown --- drivers/acpi/scan.c | 36 ++++++++++++++++++++---------------- 1 file changed, 20 insertions(+), 16 deletions(-) diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index b23825ecfa37..81aec8d66fd0 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)