linux-kernel - [PATCH v1 1/1] serial: 8250

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Date: Fri, 12 Apr 2024 20:39:31 +0300
From: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>
To: Andy Shevchenko <andriy.shevchenko@...ux.intel.com>,
	linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org
Cc: Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Jiri Slaby <jirislaby@...nel.org>
Subject: [PATCH v1 1/1] serial: 8250_dw: Deduplicate LCR checks

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@...ux.intel.com>
---
 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