This is a note to let you know that I've just added the patch titled
serial: sc16is7xx: change EFR lock to operate on each channels
to my tty git tree which can be found at
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty.git
in the tty-testing branch.
The patch will show up in the next release of the linux-next tree
(usually sometime within the next 24 hours during the week.)
The patch will be merged to the tty-next branch sometime soon,
after it passes testing, and the merge window is open.
If you have any questions about this process, please let me know.
>From 4409df5866b7ff7686ba27e449ca97a92ee063c9 Mon Sep 17 00:00:00 2001
From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Date: Mon, 11 Dec 2023 12:13:51 -0500
Subject: serial: sc16is7xx: change EFR lock to operate on each channels
Now that the driver has been converted to use one regmap per port, change
efr locking to operate on a channel basis instead of on the whole IC.
Fixes: 3837a0379533 ("serial: sc16is7xx: improve regmap debugfs by using one regmap per port")
Cc: <stable@xxxxxxxxxxxxxxx> # 6.1.x: 3837a03 serial: sc16is7xx: improve regmap debugfs by using one regmap per port
Signed-off-by: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20231211171353.2901416-5-hugo@xxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/sc16is7xx.c | 49 ++++++++++++++++++----------------
1 file changed, 26 insertions(+), 23 deletions(-)
diff --git a/drivers/tty/serial/sc16is7xx.c b/drivers/tty/serial/sc16is7xx.c
index 0a7a9aa5c9fa..0bda9b74d096 100644
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -323,6 +323,7 @@ struct sc16is7xx_one_config {
struct sc16is7xx_one {
struct uart_port port;
struct regmap *regmap;
+ struct mutex efr_lock; /* EFR registers access */
struct kthread_work tx_work;
struct kthread_work reg_work;
struct kthread_delayed_work ms_work;
@@ -342,7 +343,6 @@ struct sc16is7xx_port {
unsigned char buf[SC16IS7XX_FIFO_SIZE];
struct kthread_worker kworker;
struct task_struct *kworker_task;
- struct mutex efr_lock;
struct sc16is7xx_one p[];
};
@@ -494,7 +494,6 @@ static bool sc16is7xx_regmap_precious(struct device *dev, unsigned int reg)
static int sc16is7xx_set_baud(struct uart_port *port, int baud)
{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
u8 lcr;
u8 prescaler = 0;
@@ -518,7 +517,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
* because the bulk of the interrupt processing is run as a workqueue
* job in thread context.
*/
- mutex_lock(&s->efr_lock);
+ mutex_lock(&one->efr_lock);
lcr = sc16is7xx_port_read(port, SC16IS7XX_LCR_REG);
@@ -537,7 +536,7 @@ static int sc16is7xx_set_baud(struct uart_port *port, int baud)
/* Put LCR back to the normal mode */
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
- mutex_unlock(&s->efr_lock);
+ mutex_unlock(&one->efr_lock);
sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
SC16IS7XX_MCR_CLKSEL_BIT,
@@ -705,11 +704,10 @@ static unsigned int sc16is7xx_get_hwmctrl(struct uart_port *port)
static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
{
struct uart_port *port = &one->port;
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
unsigned long flags;
unsigned int status, changed;
- lockdep_assert_held_once(&s->efr_lock);
+ lockdep_assert_held_once(&one->efr_lock);
status = sc16is7xx_get_hwmctrl(port);
changed = status ^ one->old_mctrl;
@@ -735,15 +733,20 @@ static void sc16is7xx_update_mlines(struct sc16is7xx_one *one)
static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
{
+ bool rc = true;
struct uart_port *port = &s->p[portno].port;
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
+
+ mutex_lock(&one->efr_lock);
do {
unsigned int iir, rxlen;
- struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
iir = sc16is7xx_port_read(port, SC16IS7XX_IIR_REG);
- if (iir & SC16IS7XX_IIR_NO_INT_BIT)
- return false;
+ if (iir & SC16IS7XX_IIR_NO_INT_BIT) {
+ rc = false;
+ goto out_port_irq;
+ }
iir &= SC16IS7XX_IIR_ID_MASK;
@@ -783,15 +786,17 @@ static bool sc16is7xx_port_irq(struct sc16is7xx_port *s, int portno)
break;
}
} while (0);
- return true;
+
+out_port_irq:
+ mutex_unlock(&one->efr_lock);
+
+ return rc;
}
static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
{
struct sc16is7xx_port *s = (struct sc16is7xx_port *)dev_id;
- mutex_lock(&s->efr_lock);
-
while (1) {
bool keep_polling = false;
int i;
@@ -802,24 +807,22 @@ static irqreturn_t sc16is7xx_irq(int irq, void *dev_id)
break;
}
- mutex_unlock(&s->efr_lock);
-
return IRQ_HANDLED;
}
static void sc16is7xx_tx_proc(struct kthread_work *ws)
{
struct uart_port *port = &(to_sc16is7xx_one(ws, tx_work)->port);
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
+ struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
unsigned long flags;
if ((port->rs485.flags & SER_RS485_ENABLED) &&
(port->rs485.delay_rts_before_send > 0))
msleep(port->rs485.delay_rts_before_send);
- mutex_lock(&s->efr_lock);
+ mutex_lock(&one->efr_lock);
sc16is7xx_handle_tx(port);
- mutex_unlock(&s->efr_lock);
+ mutex_unlock(&one->efr_lock);
uart_port_lock_irqsave(port, &flags);
sc16is7xx_ier_set(port, SC16IS7XX_IER_THRI_BIT);
@@ -926,9 +929,9 @@ 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(&s->efr_lock);
+ mutex_lock(&one->efr_lock);
sc16is7xx_update_mlines(one);
- mutex_unlock(&s->efr_lock);
+ mutex_unlock(&one->efr_lock);
kthread_queue_delayed_work(&s->kworker, &one->ms_work, HZ);
}
@@ -1012,7 +1015,6 @@ static void sc16is7xx_set_termios(struct uart_port *port,
struct ktermios *termios,
const struct ktermios *old)
{
- struct sc16is7xx_port *s = dev_get_drvdata(port->dev);
struct sc16is7xx_one *one = to_sc16is7xx_one(port, port);
unsigned int lcr, flow = 0;
int baud;
@@ -1071,7 +1073,7 @@ static void sc16is7xx_set_termios(struct uart_port *port,
port->ignore_status_mask |= SC16IS7XX_LSR_BRK_ERROR_MASK;
/* As above, claim the mutex while accessing the EFR. */
- mutex_lock(&s->efr_lock);
+ mutex_lock(&one->efr_lock);
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG,
SC16IS7XX_LCR_CONF_MODE_B);
@@ -1101,7 +1103,7 @@ static void sc16is7xx_set_termios(struct uart_port *port,
/* Update LCR register */
sc16is7xx_port_write(port, SC16IS7XX_LCR_REG, lcr);
- mutex_unlock(&s->efr_lock);
+ mutex_unlock(&one->efr_lock);
/* Get baud rate generator configuration */
baud = uart_get_baud_rate(port, termios, old,
@@ -1535,7 +1537,6 @@ static int sc16is7xx_probe(struct device *dev,
s->devtype = devtype;
dev_set_drvdata(dev, s);
- mutex_init(&s->efr_lock);
kthread_init_worker(&s->kworker);
s->kworker_task = kthread_run(kthread_worker_fn, &s->kworker,
@@ -1578,6 +1579,8 @@ static int sc16is7xx_probe(struct device *dev,
goto out_ports;
}
+ mutex_init(&s->p[i].efr_lock);
+
ret = uart_get_rs485_mode(&s->p[i].port);
if (ret)
goto out_ports;
--
2.43.0
