From: Hugo Villeneuve <hvilleneuve@xxxxxxxxxxxx>
commit 4409df5866b7ff7686ba27e449ca97a92ee063c9 upstream.
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
[Hui: fixed some conflict when backporting to 5.15.y]
Signed-off-by: Hui Wang <hui.wang@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/tty/serial/sc16is7xx.c | 41 +++++++++++++++++++++++------------------
1 file changed, 23 insertions(+), 18 deletions(-)
--- a/drivers/tty/serial/sc16is7xx.c
+++ b/drivers/tty/serial/sc16is7xx.c
@@ -314,6 +314,7 @@ 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 sc16is7xx_one_config config;
@@ -329,7 +330,6 @@ 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[];
};
@@ -491,7 +491,6 @@ static bool sc16is7xx_regmap_noinc(struc
*/
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;
unsigned int prescaler = 1;
@@ -515,7 +514,7 @@ static int sc16is7xx_set_baud(struct uar
* 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);
@@ -532,7 +531,7 @@ static int sc16is7xx_set_baud(struct uar
/* 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);
/* If bit MCR_CLKSEL is set, the divide by 4 prescaler is activated. */
sc16is7xx_port_update(port, SC16IS7XX_MCR_REG,
@@ -680,14 +679,20 @@ static void sc16is7xx_handle_tx(struct u
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;
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;
@@ -722,15 +727,17 @@ static bool sc16is7xx_port_irq(struct sc
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;
@@ -741,23 +748,21 @@ static irqreturn_t sc16is7xx_irq(int irq
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);
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);
}
static void sc16is7xx_reconf_rs485(struct uart_port *port)
@@ -878,7 +883,6 @@ static void sc16is7xx_set_termios(struct
struct ktermios *termios,
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;
@@ -934,7 +938,7 @@ static void sc16is7xx_set_termios(struct
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);
@@ -957,7 +961,7 @@ static void sc16is7xx_set_termios(struct
/* 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,
@@ -1261,7 +1265,6 @@ static int sc16is7xx_probe(struct device
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,
@@ -1302,6 +1305,8 @@ static int sc16is7xx_probe(struct device
goto out_ports;
}
+ mutex_init(&s->p[i].efr_lock);
+
/* Disable all interrupts */
sc16is7xx_port_write(&s->p[i].port, SC16IS7XX_IER_REG, 0);
/* Disable TX/RX */
Patches currently in stable-queue which might be from hvilleneuve@xxxxxxxxxxxx are
queue-5.15/serial-sc16is7xx-remove-unused-line-structure-member.patch
queue-5.15/serial-sc16is7xx-improve-regmap-debugfs-by-using-one-regmap-per-port.patch
queue-5.15/serial-sc16is7xx-change-efr-lock-to-operate-on-each-channels.patch
queue-5.15/serial-sc16is7xx-remove-global-regmap-from-struct-sc16is7xx_port.patch
queue-5.15/serial-sc16is7xx-remove-wasteful-static-buffer-in-sc16is7xx_regmap_name.patch
