diff options
| author |   Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com> | 2019-05-24 14:41:29 +0530 |
|---|---|---|
| committer |   Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-06-10 19:08:32 +0200 |
| commit | 277375b864e8147975b064b513f491e2a910e66a (patch) | |
| tree | 17834ba1b86bda8da380cf3711507f78022c0749 /drivers/tty/serial | |
| parent | serial: uartps: Move the spinlock after the read of the tx empty (diff) | |
| download | linux-dev-277375b864e8147975b064b513f491e2a910e66a.tar.xz linux-dev-277375b864e8147975b064b513f491e2a910e66a.zip | |
serial: uartps: Add a timeout to the tx empty wait
In case the cable is not connected then the target gets into
an infinite wait for tx empty.
Add a timeout to the tx empty wait.
Reported-by: Jean-Francois Dagenais <jeff.dagenais@gmail.com>
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xilinx.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/xilinx_uartps.c | 14 |
1 files changed, 10 insertions, 4 deletions
diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c index 33ac898fb36e..ac3fd58f7092 100644 --- a/drivers/tty/serial/xilinx_uartps.c +++ b/drivers/tty/serial/xilinx_uartps.c @@ -26,12 +26,14 @@ #include <linux/of.h> #include <linux/module.h> #include <linux/pm_runtime.h> +#include <linux/iopoll.h> #define CDNS_UART_TTY_NAME "ttyPS" #define CDNS_UART_NAME "xuartps" #define CDNS_UART_MAJOR 0 /* use dynamic node allocation */ #define CDNS_UART_FIFO_SIZE 64 /* FIFO size */ #define CDNS_UART_REGISTER_SPACE 0x1000 +#define TX_TIMEOUT 500000 /* Rx Trigger level */ static int rx_trigger_level = 56; @@ -684,14 +686,18 @@ static void cdns_uart_set_termios(struct uart_port *port, unsigned int cval = 0; unsigned int baud, minbaud, maxbaud; unsigned long flags; - unsigned int ctrl_reg, mode_reg; + unsigned int ctrl_reg, mode_reg, val; + int err; /* Wait for the transmit FIFO to empty before making changes */ if (!(readl(port->membase + CDNS_UART_CR) & CDNS_UART_CR_TX_DIS)) { - while (!(readl(port->membase + CDNS_UART_SR) & - CDNS_UART_SR_TXEMPTY)) { - cpu_relax(); + err = readl_poll_timeout(port->membase + CDNS_UART_SR, + val, (val & CDNS_UART_SR_TXEMPTY), + 1000, TX_TIMEOUT); + if (err) { + dev_err(port->dev, "timed out waiting for tx empty"); + return; } } spin_lock_irqsave(&port->lock, flags); |