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serial: pch: Remove eg20t_port::lock.

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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>
This commit is contained in:
Sebastian Andrzej Siewior 2024-03-01 22:45:30 +01:00 committed by Greg Kroah-Hartman
parent 38f3fc2e82
commit 06d28ca0c6
1 changed files with 6 additions and 20 deletions
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26
drivers/tty/serial/pch_uart.c
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@ -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;