serial: clps711x: Give a chance to perform useful tasks during wait loop
This patch adds cond_sched() calls during wait loop to perform
other tasks.
Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c
index b0eacb8..5e6fdb1 100644
--- a/drivers/tty/serial/clps711x.c
+++ b/drivers/tty/serial/clps711x.c
@@ -368,11 +368,16 @@
static void uart_clps711x_console_putchar(struct uart_port *port, int ch)
{
struct clps711x_port *s = dev_get_drvdata(port->dev);
- u32 sysflg = 0;
- do {
+ /* Wait for FIFO is not full */
+ while (1) {
+ u32 sysflg = 0;
+
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
- } while (sysflg & SYSFLG_UTXFF);
+ if (!(sysflg & SYSFLG_UTXFF))
+ break;
+ cond_resched();
+ }
writew(ch, port->membase + UARTDR_OFFSET);
}
@@ -382,14 +387,18 @@
{
struct uart_port *port = clps711x_uart.state[co->index].uart_port;
struct clps711x_port *s = dev_get_drvdata(port->dev);
- u32 sysflg = 0;
uart_console_write(port, c, n, uart_clps711x_console_putchar);
/* Wait for transmitter to become empty */
- do {
+ while (1) {
+ u32 sysflg = 0;
+
regmap_read(s->syscon, SYSFLG_OFFSET, &sysflg);
- } while (sysflg & SYSFLG_UBUSY);
+ if (!(sysflg & SYSFLG_UBUSY))
+ break;
+ cond_resched();
+ }
}
static int uart_clps711x_console_setup(struct console *co, char *options)