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| author | Alexander Shiyan <shc_work@mail.ru> | 2014-03-11 15:30:01 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-03-17 16:13:24 -0700 |
| commit | 63e3ad3252695a2b8c01b6f6c225e4537af08b85 (patch) | |
| tree | bd4d67034f7f8b435d9be8c985dcedb9210f17af /drivers/tty/serial/clps711x.c | |
| parent | 015355b70e074a8cc11da6ae4f82d45c5160358a (diff) | |
| download | linux-63e3ad3252695a2b8c01b6f6c225e4537af08b85.tar.gz linux-63e3ad3252695a2b8c01b6f6c225e4537af08b85.tar.bz2 linux-63e3ad3252695a2b8c01b6f6c225e4537af08b85.zip | |
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>
Diffstat (limited to 'drivers/tty/serial/clps711x.c')
| -rw-r--r-- | drivers/tty/serial/clps711x.c | 21 |
1 files 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) |