Man page 9 : kfifo_dma_out_finish

kfifo_dma_out_finish - finish a DMA OUT operation

kfifo_dma_out_finish( fifo , len );

fifo
    address of the fifo to be used

len
    number of bytes transferd

This macro finish a DMA OUT operation. The out counter will be updated by the len parameter. No error checking will be done.

Note that with only one concurrent reader and one concurrent writer, you donAqt need extra locking to use these macros.