Commits
Elen Song committed 34df42f59a6
serial: at91: add rx dma support Request a cyclic dma channel for rx dma use. Use cyclic transfer is to prevent receive data overrun. We allocate a cycle dma cookie after request channel, after that, enable uart timeout interrupt in startup stage, when data successful received, the timeout callback will check the residual bytes and insert receiving datas into the framework during the transfer interval. When current descriptor finished, the dma callback will also check the residual bytes and filp the receiving data. Signed-off-by: Elen Song <elen.song@atmel.com> Signed-off-by: Ludovic Desroches <ludovic.desroches@atmel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>