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path: root/drivers/tty/serial/serial_core.c
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Diffstat (limited to 'drivers/tty/serial/serial_core.c')
-rw-r--r--drivers/tty/serial/serial_core.c87
1 files changed, 57 insertions, 30 deletions
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 0f02351c923..fbf6c5ad222 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -89,8 +89,7 @@ static void __uart_start(struct tty_struct *tty)
struct uart_state *state = tty->driver_data;
struct uart_port *port = state->uart_port;
- if (!uart_circ_empty(&state->xmit) && state->xmit.buf &&
- !tty->stopped && !tty->hw_stopped)
+ if (!tty->stopped && !tty->hw_stopped)
port->ops->start_tx(port);
}
@@ -138,6 +137,11 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
return 1;
/*
+ * Make sure the device is in D0 state.
+ */
+ uart_change_pm(state, UART_PM_STATE_ON);
+
+ /*
* Initialise and allocate the transmit and temporary
* buffer.
*/
@@ -170,8 +174,12 @@ static int uart_port_startup(struct tty_struct *tty, struct uart_state *state,
if (tty->termios.c_cflag & CBAUD)
uart_set_mctrl(uport, TIOCM_RTS | TIOCM_DTR);
}
-
- if (tty_port_cts_enabled(port)) {
+ /*
+ * if hw support flow control without software intervention,
+ * then skip the below check
+ */
+ if (tty_port_cts_enabled(port) &&
+ !(uport->flags & UPF_HARD_FLOW)) {
spin_lock_irq(&uport->lock);
if (!(uport->ops->get_mctrl(uport) & TIOCM_CTS))
tty->hw_stopped = 1;
@@ -826,25 +834,29 @@ static int uart_set_info(struct tty_struct *tty, struct tty_port *port,
* If we fail to request resources for the
* new port, try to restore the old settings.
*/
- if (retval && old_type != PORT_UNKNOWN) {
+ if (retval) {
uport->iobase = old_iobase;
uport->type = old_type;
uport->hub6 = old_hub6;
uport->iotype = old_iotype;
uport->regshift = old_shift;
uport->mapbase = old_mapbase;
- retval = uport->ops->request_port(uport);
- /*
- * If we failed to restore the old settings,
- * we fail like this.
- */
- if (retval)
- uport->type = PORT_UNKNOWN;
- /*
- * We failed anyway.
- */
- retval = -EBUSY;
+ if (old_type != PORT_UNKNOWN) {
+ retval = uport->ops->request_port(uport);
+ /*
+ * If we failed to restore the old settings,
+ * we fail like this.
+ */
+ if (retval)
+ uport->type = PORT_UNKNOWN;
+
+ /*
+ * We failed anyway.
+ */
+ retval = -EBUSY;
+ }
+
/* Added to return the correct error -Ram Gupta */
goto exit;
}
@@ -1319,9 +1331,9 @@ static void uart_close(struct tty_struct *tty, struct file *filp)
uport = state->uart_port;
port = &state->port;
- pr_debug("uart_close(%d) called\n", uport->line);
+ pr_debug("uart_close(%d) called\n", uport ? uport->line : -1);
- if (tty_port_close_start(port, tty, filp) == 0)
+ if (!port->count || tty_port_close_start(port, tty, filp) == 0)
return;
/*
@@ -1452,6 +1464,8 @@ static void uart_hangup(struct tty_struct *tty)
clear_bit(ASYNCB_NORMAL_ACTIVE, &port->flags);
spin_unlock_irqrestore(&port->lock, flags);
tty_port_tty_set(port, NULL);
+ if (!uart_console(state->uart_port))
+ uart_change_pm(state, UART_PM_STATE_OFF);
wake_up_interruptible(&port->open_wait);
wake_up_interruptible(&port->delta_msr_wait);
}
@@ -1570,12 +1584,6 @@ static int uart_open(struct tty_struct *tty, struct file *filp)
}
/*
- * Make sure the device is in D0 state.
- */
- if (port->count == 1)
- uart_change_pm(state, UART_PM_STATE_ON);
-
- /*
* Start up the serial port.
*/
retval = uart_startup(tty, state, 0);
@@ -1762,7 +1770,7 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
}
/**
- * uart_parse_options - Parse serial port baud/parity/bits/flow contro.
+ * uart_parse_options - Parse serial port baud/parity/bits/flow control.
* @options: pointer to option string
* @baud: pointer to an 'int' variable for the baud rate.
* @parity: pointer to an 'int' variable for the parity.
@@ -1830,9 +1838,13 @@ uart_set_options(struct uart_port *port, struct console *co,
/*
* Ensure that the serial console lock is initialised
* early.
+ * If this port is a console, then the spinlock is already
+ * initialised.
*/
- spin_lock_init(&port->lock);
- lockdep_set_class(&port->lock, &port_lock_key);
+ if (!(uart_console(port) && (port->cons->flags & CON_ENABLED))) {
+ spin_lock_init(&port->lock);
+ lockdep_set_class(&port->lock, &port_lock_key);
+ }
memset(&termios, 0, sizeof(struct ktermios));
@@ -2231,6 +2243,9 @@ static void uart_poll_put_char(struct tty_driver *driver, int line, char ch)
return;
port = state->uart_port;
+
+ if (ch == '\n')
+ port->ops->poll_put_char(port, '\r');
port->ops->poll_put_char(port, ch);
}
#endif
@@ -2605,7 +2620,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *uport)
/*
* Register the port whether it's detected or not. This allows
- * setserial to be used to alter this ports parameters.
+ * setserial to be used to alter this port's parameters.
*/
tty_dev = tty_port_register_device_attr(port, drv->tty_driver,
uport->line, uport->dev, port, tty_dev_attr_groups);
@@ -2641,6 +2656,7 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
{
struct uart_state *state = drv->state + uport->line;
struct tty_port *port = &state->port;
+ struct tty_struct *tty;
int ret = 0;
BUG_ON(in_interrupt());
@@ -2669,8 +2685,17 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *uport)
*/
tty_unregister_device(drv->tty_driver, uport->line);
- if (port->tty)
+ tty = tty_port_tty_get(port);
+ if (tty) {
tty_vhangup(port->tty);
+ tty_kref_put(tty);
+ }
+
+ /*
+ * If the port is used as a console, unregister it
+ */
+ if (uart_console(uport))
+ unregister_console(uport->cons);
/*
* Free the port IO and memory resources, if any.
@@ -2754,7 +2779,9 @@ void uart_handle_cts_change(struct uart_port *uport, unsigned int status)
uport->icount.cts++;
- if (tty_port_cts_enabled(port)) {
+ /* skip below code if the hw flow control is supported */
+ if (tty_port_cts_enabled(port) &&
+ !(uport->flags & UPF_HARD_FLOW)) {
if (tty->hw_stopped) {
if (status) {
tty->hw_stopped = 0;
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2025-11-04 13:06:45 +0000