USB: create attributes before sending uevent
This patch (as1087d) fixes a long-standing problem in usbcore: Device,
interface, and endpoint attributes aren't added until _after_ the
creation uevent has already been broadcast.
Unfortunately there are a few attributes which cannot be created that
early. The "descriptors" attribute is binary and so must be created
separately. The power-management attributes can't be created until
the dev/power/ group exists. And the interface string can vary from
one altsetting to another, so it has to be created dynamically.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/core/endpoint.c b/drivers/usb/core/endpoint.c
index 99e5a68..fae55a3 100644
--- a/drivers/usb/core/endpoint.c
+++ b/drivers/usb/core/endpoint.c
@@ -156,6 +156,10 @@
static struct attribute_group ep_dev_attr_grp = {
.attrs = ep_dev_attrs,
};
+static struct attribute_group *ep_dev_groups[] = {
+ &ep_dev_attr_grp,
+ NULL
+};
static int usb_endpoint_major_init(void)
{
@@ -298,6 +302,7 @@
ep_dev->desc = &endpoint->desc;
ep_dev->udev = udev;
+ ep_dev->dev.groups = ep_dev_groups;
ep_dev->dev.devt = MKDEV(usb_endpoint_major, ep_dev->minor);
ep_dev->dev.class = ep_class->class;
ep_dev->dev.parent = parent;
@@ -309,9 +314,6 @@
retval = device_register(&ep_dev->dev);
if (retval)
goto error_chrdev;
- retval = sysfs_create_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
- if (retval)
- goto error_group;
/* create the symlink to the old-style "ep_XX" directory */
sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
@@ -322,8 +324,6 @@
return retval;
error_link:
- sysfs_remove_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
-error_group:
device_unregister(&ep_dev->dev);
destroy_endpoint_class();
return retval;
@@ -348,7 +348,6 @@
sprintf(name, "ep_%02x", endpoint->desc.bEndpointAddress);
sysfs_remove_link(&ep_dev->dev.parent->kobj, name);
- sysfs_remove_group(&ep_dev->dev.kobj, &ep_dev_attr_grp);
device_unregister(&ep_dev->dev);
endpoint->ep_dev = NULL;
destroy_endpoint_class();
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 3e69266..fe47d14 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1607,6 +1607,7 @@
intf->dev.driver = NULL;
intf->dev.bus = &usb_bus_type;
intf->dev.type = &usb_if_device_type;
+ intf->dev.groups = usb_interface_groups;
intf->dev.dma_mask = dev->dev.dma_mask;
device_initialize(&intf->dev);
mark_quiesced(intf);
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index 5b20a60..c783cb1 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -538,6 +538,46 @@
.attrs = dev_attrs,
};
+/* When modifying this list, be sure to modify dev_string_attrs_are_visible()
+ * accordingly.
+ */
+static struct attribute *dev_string_attrs[] = {
+ &dev_attr_manufacturer.attr,
+ &dev_attr_product.attr,
+ &dev_attr_serial.attr,
+ NULL
+};
+
+static mode_t dev_string_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct usb_device *udev = to_usb_device(
+ container_of(kobj, struct device, kobj));
+
+ if (a == &dev_attr_manufacturer.attr) {
+ if (udev->manufacturer == NULL)
+ return 0;
+ } else if (a == &dev_attr_product.attr) {
+ if (udev->product == NULL)
+ return 0;
+ } else if (a == &dev_attr_serial.attr) {
+ if (udev->serial == NULL)
+ return 0;
+ }
+ return a->mode;
+}
+
+static struct attribute_group dev_string_attr_grp = {
+ .attrs = dev_string_attrs,
+ .is_visible = dev_string_attrs_are_visible,
+};
+
+struct attribute_group *usb_device_groups[] = {
+ &dev_attr_grp,
+ &dev_string_attr_grp,
+ NULL
+};
+
/* Binary descriptors */
static ssize_t
@@ -591,10 +631,9 @@
struct device *dev = &udev->dev;
int retval;
- retval = sysfs_create_group(&dev->kobj, &dev_attr_grp);
- if (retval)
- return retval;
-
+ /* Unforunately these attributes cannot be created before
+ * the uevent is broadcast.
+ */
retval = device_create_bin_file(dev, &dev_bin_attr_descriptors);
if (retval)
goto error;
@@ -607,21 +646,6 @@
if (retval)
goto error;
- if (udev->manufacturer) {
- retval = device_create_file(dev, &dev_attr_manufacturer);
- if (retval)
- goto error;
- }
- if (udev->product) {
- retval = device_create_file(dev, &dev_attr_product);
- if (retval)
- goto error;
- }
- if (udev->serial) {
- retval = device_create_file(dev, &dev_attr_serial);
- if (retval)
- goto error;
- }
retval = usb_create_ep_files(dev, &udev->ep0, udev);
if (retval)
goto error;
@@ -636,13 +660,9 @@
struct device *dev = &udev->dev;
usb_remove_ep_files(&udev->ep0);
- device_remove_file(dev, &dev_attr_manufacturer);
- device_remove_file(dev, &dev_attr_product);
- device_remove_file(dev, &dev_attr_serial);
remove_power_attributes(dev);
remove_persist_attributes(dev);
device_remove_bin_file(dev, &dev_bin_attr_descriptors);
- sysfs_remove_group(&dev->kobj, &dev_attr_grp);
}
/* Interface Accociation Descriptor fields */
@@ -688,17 +708,15 @@
struct device_attribute *attr, char *buf)
{
struct usb_interface *intf;
- struct usb_device *udev;
- int len;
+ char *string;
intf = to_usb_interface(dev);
- udev = interface_to_usbdev(intf);
- len = snprintf(buf, 256, "%s", intf->cur_altsetting->string);
- if (len < 0)
+ string = intf->cur_altsetting->string;
+ barrier(); /* The altsetting might change! */
+
+ if (!string)
return 0;
- buf[len] = '\n';
- buf[len+1] = 0;
- return len+1;
+ return sprintf(buf, "%s\n", string);
}
static DEVICE_ATTR(interface, S_IRUGO, show_interface_string, NULL);
@@ -727,18 +745,6 @@
}
static DEVICE_ATTR(modalias, S_IRUGO, show_modalias, NULL);
-static struct attribute *intf_assoc_attrs[] = {
- &dev_attr_iad_bFirstInterface.attr,
- &dev_attr_iad_bInterfaceCount.attr,
- &dev_attr_iad_bFunctionClass.attr,
- &dev_attr_iad_bFunctionSubClass.attr,
- &dev_attr_iad_bFunctionProtocol.attr,
- NULL,
-};
-static struct attribute_group intf_assoc_attr_grp = {
- .attrs = intf_assoc_attrs,
-};
-
static struct attribute *intf_attrs[] = {
&dev_attr_bInterfaceNumber.attr,
&dev_attr_bAlternateSetting.attr,
@@ -753,6 +759,37 @@
.attrs = intf_attrs,
};
+static struct attribute *intf_assoc_attrs[] = {
+ &dev_attr_iad_bFirstInterface.attr,
+ &dev_attr_iad_bInterfaceCount.attr,
+ &dev_attr_iad_bFunctionClass.attr,
+ &dev_attr_iad_bFunctionSubClass.attr,
+ &dev_attr_iad_bFunctionProtocol.attr,
+ NULL,
+};
+
+static mode_t intf_assoc_attrs_are_visible(struct kobject *kobj,
+ struct attribute *a, int n)
+{
+ struct usb_interface *intf = to_usb_interface(
+ container_of(kobj, struct device, kobj));
+
+ if (intf->intf_assoc == NULL)
+ return 0;
+ return a->mode;
+}
+
+static struct attribute_group intf_assoc_attr_grp = {
+ .attrs = intf_assoc_attrs,
+ .is_visible = intf_assoc_attrs_are_visible,
+};
+
+struct attribute_group *usb_interface_groups[] = {
+ &intf_attr_grp,
+ &intf_assoc_attr_grp,
+ NULL
+};
+
static inline void usb_create_intf_ep_files(struct usb_interface *intf,
struct usb_device *udev)
{
@@ -777,23 +814,21 @@
int usb_create_sysfs_intf_files(struct usb_interface *intf)
{
- struct device *dev = &intf->dev;
struct usb_device *udev = interface_to_usbdev(intf);
struct usb_host_interface *alt = intf->cur_altsetting;
int retval;
if (intf->sysfs_files_created)
return 0;
- retval = sysfs_create_group(&dev->kobj, &intf_attr_grp);
- if (retval)
- return retval;
+ /* The interface string may be present in some altsettings
+ * and missing in others. Hence its attribute cannot be created
+ * before the uevent is broadcast.
+ */
if (alt->string == NULL)
alt->string = usb_cache_string(udev, alt->desc.iInterface);
if (alt->string)
- retval = device_create_file(dev, &dev_attr_interface);
- if (intf->intf_assoc)
- retval = sysfs_create_group(&dev->kobj, &intf_assoc_attr_grp);
+ retval = device_create_file(&intf->dev, &dev_attr_interface);
usb_create_intf_ep_files(intf, udev);
intf->sysfs_files_created = 1;
return 0;
@@ -807,7 +842,5 @@
return;
usb_remove_intf_ep_files(intf);
device_remove_file(dev, &dev_attr_interface);
- sysfs_remove_group(&dev->kobj, &intf_attr_grp);
- sysfs_remove_group(&intf->dev.kobj, &intf_assoc_attr_grp);
intf->sysfs_files_created = 0;
}
diff --git a/drivers/usb/core/usb.c b/drivers/usb/core/usb.c
index 1f0db51..3257743 100644
--- a/drivers/usb/core/usb.c
+++ b/drivers/usb/core/usb.c
@@ -291,6 +291,7 @@
device_initialize(&dev->dev);
dev->dev.bus = &usb_bus_type;
dev->dev.type = &usb_device_type;
+ dev->dev.groups = usb_device_groups;
dev->dev.dma_mask = bus->controller->dma_mask;
set_dev_node(&dev->dev, dev_to_node(bus->controller));
dev->state = USB_STATE_ATTACHED;
diff --git a/drivers/usb/core/usb.h b/drivers/usb/core/usb.h
index 1bf8ccb..1a8bc21 100644
--- a/drivers/usb/core/usb.h
+++ b/drivers/usb/core/usb.h
@@ -130,6 +130,10 @@
/* for labeling diagnostics */
extern const char *usbcore_name;
+/* sysfs stuff */
+extern struct attribute_group *usb_device_groups[];
+extern struct attribute_group *usb_interface_groups[];
+
/* usbfs stuff */
extern struct mutex usbfs_mutex;
extern struct usb_driver usbfs_driver;