Extern or forward variable declaration at drivers/usb/gadget/u_f.h, line 19 References: drivers/usb/gadget/f_hid.c, line 61 drivers/usb/gadget/f_hid.c, line 62 drivers/usb/gadget/f_hid.c, line 229 drivers/usb/gadget/f_hid.c, line 339 drivers/usb/gadget/f_hid.c, line 345 drivers/usb/gadget/f_hid.c, line 557 drivers/usb/gadget/f_loopback.c, line 40 drivers/usb/gadget/f_loopback.c, line 41 drivers/usb/gadget/f_loopback.c, line 246 drivers/usb/gadget/f_loopback.c, line 305 drivers/usb/gadget/f_loopback.c, line 314 drivers/usb/gadget/f_midi.c, line 73 drivers/usb/gadget/f_midi.c, line 196 drivers/usb/gadget/f_midi.c, line 202 drivers/usb/gadget/f_midi.c, line 215 drivers/usb/gadget/f_midi.c, line 231 drivers/usb/gadget/f_midi.c, line 245 drivers/usb/gadget/f_midi.c, line 298 drivers/usb/gadget/f_midi.c, line 534 drivers/usb/gadget/f_sourcesink.c, line 54 drivers/usb/gadget/f_sourcesink.c, line 55 drivers/usb/gadget/f_sourcesink.c, line 56 drivers/usb/gadget/f_sourcesink.c, line 57 drivers/usb/gadget/f_sourcesink.c, line 305 drivers/usb/gadget/f_sourcesink.c, line 310 drivers/usb/gadget/f_sourcesink.c, line 316 drivers/usb/gadget/f_sourcesink.c, line 330 drivers/usb/gadget/f_sourcesink.c, line 330 drivers/usb/gadget/f_sourcesink.c, line 331 drivers/usb/gadget/f_sourcesink.c, line 331 drivers/usb/gadget/f_sourcesink.c, line 530 drivers/usb/gadget/f_sourcesink.c, line 548 drivers/usb/gadget/f_sourcesink.c, line 606 drivers/usb/gadget/f_sourcesink.c, line 675 drivers/usb/gadget/u_f.c, line 17 drivers/usb/gadget/u_f.h, line 19 drivers/usb/gadget/u_f.h, line 22