[PATCH v4 2/3] serial: 8250_dw: Simplify the ref clock rate setting procedure

From: Serge Semin
Date: Tue May 26 2020 - 12:03:43 EST


Really instead of twice checking the clk_round_rate() return value
we could do it once, and if it isn't error the clock rate can be changed.
By doing so we decrease a number of ret-value tests and remove a weird
goto-based construction implemented in the dw8250_set_termios() method.

Signed-off-by: Serge Semin <Sergey.Semin@xxxxxxxxxxxxxxxxxxxx>
Cc: Alexey Malahov <Alexey.Malahov@xxxxxxxxxxxxxxxxxxxx>
Cc: Thomas Bogendoerfer <tsbogend@xxxxxxxxxxxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Cc: Maxime Ripard <mripard@xxxxxxxxxx>
Cc: Will Deacon <will@xxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxxx
Cc: linux-arm-kernel@xxxxxxxxxxxxxxxxxxx

---

Changelog v3:
- This is a new patch.
---
drivers/tty/serial/8250/8250_dw.c | 15 ++++-----------
1 file changed, 4 insertions(+), 11 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index aab3cccc6789..12866083731d 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -282,20 +282,13 @@ static void dw8250_set_termios(struct uart_port *p, struct ktermios *termios,

clk_disable_unprepare(d->clk);
rate = clk_round_rate(d->clk, baud * 16);
- if (rate < 0)
- ret = rate;
- else if (rate == 0)
- ret = -ENOENT;
- else
+ if (rate > 0) {
ret = clk_set_rate(d->clk, rate);
+ if (!ret)
+ p->uartclk = rate;
+ }
clk_prepare_enable(d->clk);

- if (ret)
- goto out;
-
- p->uartclk = rate;
-
-out:
p->status &= ~UPSTAT_AUTOCTS;
if (termios->c_cflag & CRTSCTS)
p->status |= UPSTAT_AUTOCTS;
--
2.26.2