serial: pch: Remove eg20t_port::lock.

The struct eg20t_port has a spinlock_t which is used for locking while
access I/O of the device. Then there is the uart_portlock which is
sometimes and nests within eg20t_port's lock.

The uart_port lock is not used while using the struct in
pch_uart_hal_read() which might be okay. Then both locks are used in
pch_console_write() which looks odd especially the double try_lock part.

All in all it looks like the uart_port's lock could replace eg20t_port's
lock and simplify the code.

Remove eg20t_port::lock and use uart_port's lock for the lock scope.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-18-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/tty/serial/pch_uart.c b/drivers/tty/serial/pch_uart.c
index 3911703918764780853f76f06905895da5d827ee..92cb3c623cc311c9d49e341143d80c285c6e38f9 100644 (file)
--- a/drivers/tty/serial/pch_uart.c
+++ b/drivers/tty/serial/pch_uart.c
@@ -237,9 +237,6 @@ struct eg20t_port {
 
 #define IRQ_NAME_SIZE 17
        char                            irq_name[IRQ_NAME_SIZE];
-
-       /* protect the eg20t_port private structure and io access to membase */
-       spinlock_t lock;
 };
 
 /**
@@ -1013,7 +1010,7 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
        int next = 1;
        u8 msr;
 
-       spin_lock(&priv->lock);
+       uart_port_lock(&priv->port);
        handled = 0;
        while (next) {
                iid = pch_uart_hal_get_iid(priv);
@@ -1073,7 +1070,7 @@ static irqreturn_t pch_uart_interrupt(int irq, void *dev_id)
                handled |= (unsigned int)ret;
        }
 
-       spin_unlock(&priv->lock);
+       uart_port_unlock(&priv->port);
        return IRQ_RETVAL(handled);
 }
 
@@ -1184,9 +1181,9 @@ static void pch_uart_break_ctl(struct uart_port *port, int ctl)
        unsigned long flags;
 
        priv = container_of(port, struct eg20t_port, port);
-       spin_lock_irqsave(&priv->lock, flags);
+       uart_port_lock_irqsave(&priv->port, &flags);
        pch_uart_hal_set_break(priv, ctl);
-       spin_unlock_irqrestore(&priv->lock, flags);
+       uart_port_unlock_irqrestore(&priv->port, flags);
 }
 
 /* Grab any interrupt resources and initialise any low level driver state. */
@@ -1336,8 +1333,7 @@ static void pch_uart_set_termios(struct uart_port *port,
 
        baud = uart_get_baud_rate(port, termios, old, 0, port->uartclk / 16);
 
-       spin_lock_irqsave(&priv->lock, flags);
-       uart_port_lock(port);
+       uart_port_lock_irqsave(port, &flags);
 
        uart_update_timeout(port, termios->c_cflag, baud);
        rtn = pch_uart_hal_set_line(priv, baud, parity, bits, stb);
@@ -1350,8 +1346,7 @@ static void pch_uart_set_termios(struct uart_port *port,
                tty_termios_encode_baud_rate(termios, baud, baud);
 
 out:
-       uart_port_unlock(port);
-       spin_unlock_irqrestore(&priv->lock, flags);
+       uart_port_unlock_irqrestore(port, flags);
 }
 
 static const char *pch_uart_type(struct uart_port *port)
@@ -1555,7 +1550,6 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
 {
        struct eg20t_port *priv;
        unsigned long flags;
-       int priv_locked = 1;
        int port_locked = 1;
        u8 ier;
 
@@ -1565,15 +1559,11 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
 
        local_irq_save(flags);
        if (priv->port.sysrq) {
-               /* call to uart_handle_sysrq_char already took the priv lock */
-               priv_locked = 0;
                /* serial8250_handle_port() already took the port lock */
                port_locked = 0;
        } else if (oops_in_progress) {
-               priv_locked = spin_trylock(&priv->lock);
                port_locked = uart_port_trylock(&priv->port);
        } else {
-               spin_lock(&priv->lock);
                uart_port_lock(&priv->port);
        }
 
@@ -1595,8 +1585,6 @@ pch_console_write(struct console *co, const char *s, unsigned int count)
 
        if (port_locked)
                uart_port_unlock(&priv->port);
-       if (priv_locked)
-               spin_unlock(&priv->lock);
        local_irq_restore(flags);
 }
 
@@ -1694,8 +1682,6 @@ static struct eg20t_port *pch_uart_init_port(struct pci_dev *pdev,
        pci_enable_msi(pdev);
        pci_set_master(pdev);
 
-       spin_lock_init(&priv->lock);
-
        iobase = pci_resource_start(pdev, 0);
        mapbase = pci_resource_start(pdev, 1);
        priv->mapbase = mapbase;