USB: keep track of whether interface sysfs files exist
This patch (as1009) solves the problem of multiple registrations for
USB sysfs files in a more satisfying way than the existing code. It
simply adds a flag to keep track of whether or not the files have been
created; that way the files can be created or removed as needed.
Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
index 316a746..40fd39d 100644
--- a/drivers/usb/core/message.c
+++ b/drivers/usb/core/message.c
@@ -1172,7 +1172,6 @@
struct usb_host_interface *alt;
int ret;
int manual = 0;
- int changed;
if (dev->state == USB_STATE_SUSPENDED)
return -EHOSTUNREACH;
@@ -1212,8 +1211,7 @@
*/
/* prevent submissions using previous endpoint settings */
- changed = (iface->cur_altsetting != alt);
- if (changed && device_is_registered(&iface->dev))
+ if (iface->cur_altsetting != alt && device_is_registered(&iface->dev))
usb_remove_sysfs_intf_files(iface);
usb_disable_interface(dev, iface);
@@ -1250,7 +1248,7 @@
* (Likewise, EP0 never "halts" on well designed devices.)
*/
usb_enable_interface(dev, iface);
- if (changed && device_is_registered(&iface->dev))
+ if (device_is_registered(&iface->dev))
usb_create_sysfs_intf_files(iface);
return 0;
@@ -1641,12 +1639,6 @@
intf->dev.bus_id, ret);
continue;
}
-
- /* The driver's probe method can call usb_set_interface(),
- * which would mean the interface's sysfs files are already
- * created. Just in case, we'll remove them first.
- */
- usb_remove_sysfs_intf_files(intf);
usb_create_sysfs_intf_files(intf);
}
diff --git a/drivers/usb/core/sysfs.c b/drivers/usb/core/sysfs.c
index b04afd0..32bd130 100644
--- a/drivers/usb/core/sysfs.c
+++ b/drivers/usb/core/sysfs.c
@@ -735,6 +735,8 @@
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;
@@ -746,6 +748,7 @@
if (intf->intf_assoc)
retval = sysfs_create_group(&dev->kobj, &intf_assoc_attr_grp);
usb_create_intf_ep_files(intf, udev);
+ intf->sysfs_files_created = 1;
return 0;
}
@@ -753,8 +756,11 @@
{
struct device *dev = &intf->dev;
+ if (!intf->sysfs_files_created)
+ 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/include/linux/usb.h b/include/linux/usb.h
index c5c8f16..416ee76 100644
--- a/include/linux/usb.h
+++ b/include/linux/usb.h
@@ -157,6 +157,7 @@
* bound to */
enum usb_interface_condition condition; /* state of binding */
unsigned is_active:1; /* the interface is not suspended */
+ unsigned sysfs_files_created:1; /* the sysfs attributes exist */
unsigned needs_remote_wakeup:1; /* driver requires remote wakeup */
struct device dev; /* interface specific device info */
