DMA_STATUS_TU     236 drivers/net/ethernet/calxeda/xgmac.c #define DMA_STATUS_TU		0x00000004	/* Transmit Buffer Unavail */
DMA_STATUS_TU     124 drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h #define DMA_STATUS_TU	0x00000004	/* Transmit Buffer Unavailable */