VFF_STOP 414 drivers/dma/mediatek/mtk-uart-apdma.c mtk_uart_apdma_write(c, VFF_STOP, VFF_STOP_B); VFF_STOP 421 drivers/dma/mediatek/mtk-uart-apdma.c mtk_uart_apdma_write(c, VFF_STOP, VFF_STOP_CLR_B);