Extern or forward variable declaration include/linux/ring_buffer.h, line 8 [usage...] Structure drivers/serial/ioc3_serial.c, line 287 [usage...] drivers/serial/ioc4_serial.c, line 620 [usage...] kernel/trace/ring_buffer.c, line 441 [usage...] Class, struct, or union member drivers/staging/frontier/alphatrack.c, line 142 [usage...] drivers/staging/frontier/tranzport.c, line 129 [usage...] drivers/usb/misc/ldusb.c, line 150 [usage...]