The DMA RX timeout calculation is done based on FIFO buffer size and port timeout when setting up DMA. However, both variables are not necessarily initialized at DMA initialization time, which can lead to a division by zero. Move the timeout calculation to set_termios where both variables are initialized. Signed-off-by: Stefan Agner <stefan@xxxxxxxx> --- This happens only after eDMA is fixed. Hence if the eDMA patch makes it into 3.16, it would be good to have this one in 3.16 too... http://lists.infradead.org/pipermail/linux-arm-kernel/2014-July/268199.html drivers/tty/serial/fsl_lpuart.c | 18 +++++++++++------- 1 file changed, 11 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/fsl_lpuart.c b/drivers/tty/serial/fsl_lpuart.c index 49385c8..6b462a9 100644 --- a/drivers/tty/serial/fsl_lpuart.c +++ b/drivers/tty/serial/fsl_lpuart.c @@ -724,13 +724,6 @@ static int lpuart_dma_rx_request(struct uart_port *port) sport->dma_rx_buf_bus = dma_bus; sport->dma_rx_in_progress = 0; - sport->dma_rx_timeout = (sport->port.timeout - HZ / 50) * - FSL_UART_RX_DMA_BUFFER_SIZE * 3 / - sport->rxfifo_size / 2; - - if (sport->dma_rx_timeout < msecs_to_jiffies(20)) - sport->dma_rx_timeout = msecs_to_jiffies(20); - return 0; } @@ -922,6 +915,17 @@ lpuart_set_termios(struct uart_port *port, struct ktermios *termios, /* update the per-port timeout */ uart_update_timeout(port, termios->c_cflag, baud); + if (sport->lpuart_dma_use) { + /* Calculate delay for 1.5 DMA buffers */ + sport->dma_rx_timeout = (sport->port.timeout - HZ / 50) * + FSL_UART_RX_DMA_BUFFER_SIZE * 3 / + sport->rxfifo_size / 2; + dev_dbg(port->dev, "DMA Rx t-out %ums, tty t-out %u jiffies\n", + sport->dma_rx_timeout * 1000 / HZ, sport->port.timeout); + if (sport->dma_rx_timeout < msecs_to_jiffies(20)) + sport->dma_rx_timeout = msecs_to_jiffies(20); + } + /* wait transmit engin complete */ while (!(readb(sport->port.membase + UARTSR1) & UARTSR1_TC)) barrier(); -- 2.0.1 -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
