From: Suneel <[email protected]> Changes to use the 64 byte FIFO depth and fix the issue by clearing the txempty interrupt in isr status for tx after filling in data in start_tx function
Signed-off-by: Suneel Garapati <[email protected]> Signed-off-by: Soren Brinkmann <[email protected]> --- I fixed some style issues of the original patch. --- drivers/tty/serial/xilinx_uartps.c | 30 +++++++++++++++++++++++------- 1 file changed, 23 insertions(+), 7 deletions(-) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 62259f37ddda..6e8ec6e9d5a2 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -33,12 +33,22 @@ #define XUARTPS_MAJOR 0 /* use dynamic node allocation */ #define XUARTPS_MINOR 0 /* works best with devtmpfs */ #define XUARTPS_NR_PORTS 2 -#define XUARTPS_FIFO_SIZE 16 /* FIFO size */ +#define XUARTPS_FIFO_SIZE 64 /* FIFO size */ #define XUARTPS_REGISTER_SPACE 0xFFF #define xuartps_readl(offset) ioread32(port->membase + offset) #define xuartps_writel(val, offset) iowrite32(val, port->membase + offset) +/* Rx Trigger level */ +static int rx_trigger_level = 56; +module_param(rx_trigger_level, uint, S_IRUGO); +MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes"); + +/* Rx Timeout */ +static int rx_timeout = 10; +module_param(rx_timeout, uint, S_IRUGO); +MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255"); + /********************************Register Map********************************/ /** UART * @@ -394,7 +404,7 @@ static void xuartps_start_tx(struct uart_port *port) port->state->xmit.tail = (port->state->xmit.tail + 1) & (UART_XMIT_SIZE - 1); } - + xuartps_writel(XUARTPS_IXR_TXEMPTY, XUARTPS_ISR_OFFSET); /* Enable the TX Empty interrupt */ xuartps_writel(XUARTPS_IXR_TXEMPTY, XUARTPS_IER_OFFSET); @@ -528,7 +538,7 @@ static void xuartps_set_termios(struct uart_port *port, | (XUARTPS_CR_TX_EN | XUARTPS_CR_RX_EN), XUARTPS_CR_OFFSET); - xuartps_writel(10, XUARTPS_RXTOUT_OFFSET); + xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET); port->read_status_mask = XUARTPS_IXR_TXEMPTY | XUARTPS_IXR_RXTRIG | XUARTPS_IXR_OVERRUN | XUARTPS_IXR_TOUT; @@ -631,11 +641,17 @@ static int xuartps_startup(struct uart_port *port) | XUARTPS_MR_PARITY_NONE | XUARTPS_MR_CHARLEN_8_BIT, XUARTPS_MR_OFFSET); - /* Set the RX FIFO Trigger level to 14 assuming FIFO size as 16 */ - xuartps_writel(14, XUARTPS_RXWM_OFFSET); + /* + * Set the RX FIFO Trigger level to use most of the FIFO, but it + * can be tuned with a module parameter + */ + xuartps_writel(rx_trigger_level, XUARTPS_RXWM_OFFSET); - /* Receive Timeout register is enabled with value of 10 */ - xuartps_writel(10, XUARTPS_RXTOUT_OFFSET); + /* + * Receive Timeout register is enabled but it + * can be tuned with a module parameter + */ + xuartps_writel(rx_timeout, XUARTPS_RXTOUT_OFFSET); /* Clear out any pending interrupts before enabling them */ xuartps_writel(xuartps_readl(XUARTPS_ISR_OFFSET), XUARTPS_ISR_OFFSET); -- 1.8.4.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
