usb: gadget: function: f_fs: Let ffs_epfile_ioctl wait for enable.

This allows users to make an ioctl call as the first action on a connection. Ex, some functions might want to get endpoint size before making any i/os. Previously, calling ioctls before read/write would depending on the timing of endpoints being enabled. ESHUTDOWN is now a possible return value and ENODEV is not, so change docs accordingly.

Jerry Zhang committed 9 years ago

Commit 222155d1 parent 8a8b1612 files · +58 −42Browse files

Showing the changes to include/uapi/linux (1 of 2 files). Show all

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include/uapi/linux/usb/functionfs.h+4−3

 #define	FUNCTIONFS_INTERFACE_REVMAP	_IO('g', 128)
 /*
- * Returns real bEndpointAddress of an endpoint.  If function is not
+ * Returns real bEndpointAddress of an endpoint. If endpoint shuts down
- * active returns -ENODEV.
+ * during the call, returns -ESHUTDOWN.
  */
 #define	FUNCTIONFS_ENDPOINT_REVMAP	_IO('g', 129)
 /*
- * Returns endpoint descriptor. If function is not active returns -ENODEV.
+ * Returns endpoint descriptor. If endpoint shuts down during the call,
+ * returns -ESHUTDOWN.
  */
 #define	FUNCTIONFS_ENDPOINT_DESC	_IOR('g', 130, \
 					     struct usb_endpoint_descriptor)