AR_FIFOUnderrun
#define AR_FIFOUnderrun 0x00000004 /* TX FIFO underrun */
#define AR_FIFOUnderrun 0x00000004 /* TX FIFO underrun */
#define AR_FIFOUnderrun 0x00000004 /* TX FIFO underrun */
#define AR_FIFOUnderrun 0x00000004