Maxburst was not set when doing the dma slave configuration. This value is checked by the recently introduced xdmac. It causes an error when doing the slave configuration and so prevents from using dma. Signed-off-by: Ludovic Desroches <ludovic.desroches@xxxxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> # 3.12 and later --- drivers/tty/serial/atmel_serial.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c index 4e959c4..6afce7e 100644 --- a/drivers/tty/serial/atmel_serial.c +++ b/drivers/tty/serial/atmel_serial.c @@ -880,6 +880,7 @@ static int atmel_prepare_tx_dma(struct uart_port *port) config.direction = DMA_MEM_TO_DEV; config.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; config.dst_addr = port->mapbase + ATMEL_US_THR; + config.dst_maxburst = 1; ret = dmaengine_slave_config(atmel_port->chan_tx, &config); @@ -1059,6 +1060,7 @@ static int atmel_prepare_rx_dma(struct uart_port *port) config.direction = DMA_DEV_TO_MEM; config.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE; config.src_addr = port->mapbase + ATMEL_US_RHR; + config.src_maxburst = 1; ret = dmaengine_slave_config(atmel_port->chan_rx, &config); -- 2.2.0 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html