[PATCH v1 1/1] serial: 8250_dw: Deduplicate LCR checks

From: Andy Shevchenko
Date: Fri Apr 12 2024 - 13:39:43 EST


All callers of dw8250_check_lcr() perform the same check.
Deduplicate it by moving them into respective call.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
---
drivers/tty/serial/8250/8250_dw.c | 41 +++++++++++--------------------
1 file changed, 15 insertions(+), 26 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_dw.c b/drivers/tty/serial/8250/8250_dw.c
index 1300c92b8702..1e81024f8fd3 100644
--- a/drivers/tty/serial/8250/8250_dw.c
+++ b/drivers/tty/serial/8250/8250_dw.c
@@ -100,14 +100,18 @@ static void dw8250_force_idle(struct uart_port *p)
(void)p->serial_in(p, UART_RX);
}

-static void dw8250_check_lcr(struct uart_port *p, int value)
+static void dw8250_check_lcr(struct uart_port *p, int offset, int value)
{
- void __iomem *offset = p->membase + (UART_LCR << p->regshift);
+ struct dw8250_data *d = to_dw8250_data(p->private_data);
+ void __iomem *addr = p->membase + (offset << p->regshift);
int tries = 1000;

+ if (offset != UART_LCR || d->uart_16550_compatible)
+ return;
+
/* Make sure LCR write wasn't ignored */
while (tries--) {
- unsigned int lcr = p->serial_in(p, UART_LCR);
+ unsigned int lcr = p->serial_in(p, offset);

if ((value & ~UART_LCR_SPAR) == (lcr & ~UART_LCR_SPAR))
return;
@@ -116,15 +120,15 @@ static void dw8250_check_lcr(struct uart_port *p, int value)

#ifdef CONFIG_64BIT
if (p->type == PORT_OCTEON)
- __raw_writeq(value & 0xff, offset);
+ __raw_writeq(value & 0xff, addr);
else
#endif
if (p->iotype == UPIO_MEM32)
- writel(value, offset);
+ writel(value, addr);
else if (p->iotype == UPIO_MEM32BE)
- iowrite32be(value, offset);
+ iowrite32be(value, addr);
else
- writeb(value, offset);
+ writeb(value, addr);
}
/*
* FIXME: this deadlocks if port->lock is already held
@@ -158,12 +162,8 @@ static void dw8250_tx_wait_empty(struct uart_port *p)

static void dw8250_serial_out(struct uart_port *p, int offset, int value)
{
- struct dw8250_data *d = to_dw8250_data(p->private_data);
-
writeb(value, p->membase + (offset << p->regshift));
-
- if (offset == UART_LCR && !d->uart_16550_compatible)
- dw8250_check_lcr(p, value);
+ dw8250_check_lcr(p, offset, value);
}

static void dw8250_serial_out38x(struct uart_port *p, int offset, int value)
@@ -194,26 +194,19 @@ static unsigned int dw8250_serial_inq(struct uart_port *p, int offset)

static void dw8250_serial_outq(struct uart_port *p, int offset, int value)
{
- struct dw8250_data *d = to_dw8250_data(p->private_data);
-
value &= 0xff;
__raw_writeq(value, p->membase + (offset << p->regshift));
/* Read back to ensure register write ordering. */
__raw_readq(p->membase + (UART_LCR << p->regshift));

- if (offset == UART_LCR && !d->uart_16550_compatible)
- dw8250_check_lcr(p, value);
+ dw8250_check_lcr(p, offset, value);
}
#endif /* CONFIG_64BIT */

static void dw8250_serial_out32(struct uart_port *p, int offset, int value)
{
- struct dw8250_data *d = to_dw8250_data(p->private_data);
-
writel(value, p->membase + (offset << p->regshift));
-
- if (offset == UART_LCR && !d->uart_16550_compatible)
- dw8250_check_lcr(p, value);
+ dw8250_check_lcr(p, offset, value);
}

static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)
@@ -225,12 +218,8 @@ static unsigned int dw8250_serial_in32(struct uart_port *p, int offset)

static void dw8250_serial_out32be(struct uart_port *p, int offset, int value)
{
- struct dw8250_data *d = to_dw8250_data(p->private_data);
-
iowrite32be(value, p->membase + (offset << p->regshift));
-
- if (offset == UART_LCR && !d->uart_16550_compatible)
- dw8250_check_lcr(p, value);
+ dw8250_check_lcr(p, offset, value);
}

static unsigned int dw8250_serial_in32be(struct uart_port *p, int offset)
--
2.43.0.rc1.1336.g36b5255a03ac