From 63e3ad3252695a2b8c01b6f6c225e4537af08b85 Mon Sep 17 00:00:00 2001 From: Alexander Shiyan Date: Tue, 11 Mar 2014 15:30:01 +0400 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/clps711x.c | 21 +++++++++++++++------ 1 file changed, 15 insertions(+), 6 deletions(-) diff --git a/drivers/tty/serial/clps711x.c b/drivers/tty/serial/clps711x.c index b0eacb83f831..5e6fdb1ea73b 100644 --- a/drivers/tty/serial/clps711x.c +++ b/drivers/tty/serial/clps711x.c @@ -368,11 +368,16 @@ static const struct uart_ops uart_clps711x_ops = { 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 @@ static void uart_clps711x_console_write(struct console *co, const char *c, { 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) -- 2.34.1