linux-kernel - [PATCH 03/15] serial: sc16is7xx: rename EFR mutex with generic name

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Message-Id: <20250924153740.806444-4-hugo@hugovil.com>
Date: Wed, 24 Sep 2025 11:37:28 -0400
From: Hugo Villeneuve <hugo@...ovil.com>
To: gregkh@...uxfoundation.org,
	jirislaby@...nel.org,
	fvallee@...rea.fr
Cc: linux-kernel@...r.kernel.org,
	linux-serial@...r.kernel.org,
	hugo@...ovil.com,
	Hugo Villeneuve <hvilleneuve@...onoff.com>
Subject: [PATCH 03/15] serial: sc16is7xx: rename EFR mutex with generic name

From: Hugo Villeneuve <hvilleneuve@...onoff.com>

This mutex is used as a lock when accessing registers that share the same
address space, not necessarily EFR registers.

For example, address 0x06 is shared by MSR, TCR and XOFF1 registers,
independently of EFR.

Rename the mutex with a more generic name to avoid misinterpreting its
usage.

Signed-off-by: Hugo Villeneuve <hvilleneuve@...onoff.com>
---
 drivers/tty/serial/sc16is7xx.c | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 330d95446f1d7..26b34f23ed5fe 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -330,7 +330,7 @@ struct sc16is7xx_one_config {
 struct sc16is7xx_one {
 	struct uart_port		port;
 	struct regmap			*regmap;
-	struct mutex			efr_lock; /* EFR registers access */
+	struct mutex			lock; /* For registers sharing same address space. */
 	struct kthread_work		tx_work;
 	struct kthread_work		reg_work;
 	struct kthread_delayed_work	ms_work;
@@ -438,7 +438,7 @@ static void sc16is7xx_efr_lock(struct uart_port *port)
 {
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&one->lock);
 
 	/* Backup content of LCR. */
 	one->old_lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
@@ -460,7 +460,7 @@ static void sc16is7xx_efr_unlock(struct uart_port *port)
 	/* Restore original content of LCR */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, one->old_lcr);
 
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&one->lock);
 }
 
 static void sc16is7xx_ier_clear(struct uart_port *port, u8 bit)
@@ -595,7 +595,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 			      SC16IS7XX_MCR_CLKSEL_BIT,
 			      prescaler == 1 ? 0 : SC16IS7XX_MCR_CLKSEL_BIT);
 
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&one->lock);
 
 	/* Backup LCR and access special register set (DLL/DLH) */
 	lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
@@ -611,7 +611,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
 	/* Restore LCR and access to general register set */
 	sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
 
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&one->lock);
 
 	return DIV_ROUND_CLOSEST((clk / prescaler) / 16, div);
 }
@@ -758,7 +758,7 @@ static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
 	unsigned long flags;
 	unsigned int status, changed;
 
-	lockdep_assert_held_once(&one->efr_lock);
+	lockdep_assert_held_once(&one->lock);
 
 	status = sc16is7xx_get_hwmctrl(port);
 	changed = status ^ one->old_mctrl;
@@ -789,7 +789,7 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 	struct uart_port *port = &s->p[portno].port;
 	struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
 
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&one->lock);
 
 	iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
 	if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
@@ -836,7 +836,7 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
 	}
 
 out_port_irq:
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&one->lock);
 
 	return rc;
 }
@@ -880,9 +880,9 @@ static void sc16is7xx_tx_proc(struct kthread_work *ws)
 	    (port->rs485.delay_rts_before_send > 0))
 		msleep(port->rs485.delay_rts_before_send);
 
-	mutex_lock(&one->efr_lock);
+	mutex_lock(&one->lock);
 	sc16is7xx_handle_tx(port);
-	mutex_unlock(&one->efr_lock);
+	mutex_unlock(&one->lock);
 }
 
 static void sc16is7xx_reconf_rs485(struct uart_port *port)
@@ -949,9 +949,9 @@ static void sc16is7xx_ms_proc(struct kthread_work *ws)
 	struct sc16is7xx_port *s = dev_get_drvdata(one->port.dev);
 
 	if (one->port.state) {
-		mutex_lock(&one->efr_lock);
+		mutex_lock(&one->lock);
 		sc16is7xx_update_mlines(one);
-		mutex_unlock(&one->efr_lock);
+		mutex_unlock(&one->lock);
 
 		kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
 	}
@@ -1625,7 +1625,7 @@ int sc16is7xx_probe(struct device *dev, const struct sc16is7xx_devtype *devtype,
 		s->p[i].old_mctrl	= 0;
 		s->p[i].regmap		= regmaps[i];
 
-		mutex_init(&s->p[i].efr_lock);
+		mutex_init(&s->p[i].lock);
 
 		ret = uart_get_rs485_mode(&s->p[i].port);
 		if (ret)
-- 
2.39.5