From stern@rowland.harvard.edu Mon Nov 26 21:35:59 2007 From: Alan Stern Date: Tue, 6 Nov 2007 11:43:42 -0500 (EST) Subject: USB: keep track of whether interface sysfs files exist To: Greg KH Message-ID: 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 --- drivers/usb/core/message.c | 12 ++---------- drivers/usb/core/sysfs.c | 6 ++++++ include/linux/usb.h | 1 + 3 files changed, 9 insertions(+), 10 deletions(-) --- a/drivers/usb/core/message.c +++ b/drivers/usb/core/message.c @@ -1172,7 +1172,6 @@ int usb_set_interface(struct usb_device struct usb_host_interface *alt; int ret; int manual = 0; - int changed; if (dev->state == USB_STATE_SUSPENDED) return -EHOSTUNREACH; @@ -1212,8 +1211,7 @@ int usb_set_interface(struct usb_device */ /* 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 @@ int usb_set_interface(struct usb_device * (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 @@ free_interfaces: 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); } --- a/drivers/usb/core/sysfs.c +++ b/drivers/usb/core/sysfs.c @@ -735,6 +735,8 @@ int usb_create_sysfs_intf_files(struct u 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 @@ int usb_create_sysfs_intf_files(struct u 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 @@ void usb_remove_sysfs_intf_files(struct { 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; } --- a/include/linux/usb.h +++ b/include/linux/usb.h @@ -157,6 +157,7 @@ struct usb_interface { * 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 */