From: Vlad Lungu <[email protected]> This allows KDB/KGDB to run.
Signed-off-by: Vlad Lungu <[email protected]> Signed-off-by: Soren Brinkmann <[email protected]> --- This is squashed from these original patches: tty: xuartps: Add polled mode support for xuartps This allows KDB/KGDB to run. There is a bug somewhere that blocks KDB when paging; set the LINES environment variable to a big value and scroll in your terminal. Signed-off-by: Vlad Lungu <[email protected]> and tty: xuartps: Fix poll read This fixes the KDB paging issue. Signed-off-by: Vlad Lungu <[email protected]> Additionally I fixed a few style issues. --- drivers/tty/serial/xilinx_uartps.c | 52 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 5d5557af4d22..62259f37ddda 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -775,6 +775,54 @@ static void xuartps_enable_ms(struct uart_port *port) /* N/A */ } +#ifdef CONFIG_CONSOLE_POLL +static int xuartps_poll_get_char(struct uart_port *port) +{ + u32 imr; + int c; + + /* Disable all interrupts */ + imr = xuartps_readl(XUARTPS_IMR_OFFSET); + xuartps_writel(imr, XUARTPS_IDR_OFFSET); + + /* Check if FIFO is empty */ + if (xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_RXEMPTY) + c = NO_POLL_CHAR; + else /* Read a character */ + c = (unsigned char) xuartps_readl(XUARTPS_FIFO_OFFSET); + + /* Enable interrupts */ + xuartps_writel(imr, XUARTPS_IER_OFFSET); + + return c; +} + +static void xuartps_poll_put_char(struct uart_port *port, unsigned char c) +{ + u32 imr; + + /* Disable all interrupts */ + imr = xuartps_readl(XUARTPS_IMR_OFFSET); + xuartps_writel(imr, XUARTPS_IDR_OFFSET); + + /* Wait until FIFO is empty */ + while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY)) + cpu_relax(); + + /* Write a character */ + xuartps_writel(c, XUARTPS_FIFO_OFFSET); + + /* Wait until FIFO is empty */ + while (!(xuartps_readl(XUARTPS_SR_OFFSET) & XUARTPS_SR_TXEMPTY)) + cpu_relax(); + + /* Enable interrupts */ + xuartps_writel(imr, XUARTPS_IER_OFFSET); + + return; +} +#endif + /** The UART operations structure */ static struct uart_ops xuartps_ops = { @@ -807,6 +855,10 @@ static struct uart_ops xuartps_ops = { .config_port = xuartps_config_port, /* Configure when driver * adds a xuartps port */ +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = xuartps_poll_get_char, + .poll_put_char = xuartps_poll_put_char, +#endif }; static struct uart_port xuartps_port[2]; -- 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/
