X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=drivers%2Fserial%2Fserial_core.c;h=eab032733790d5524ac9f14e8596c1a5a62e462c;hb=e616c6303306df62223ebe2e68bb2f19c420dd81;hp=f7263e104d81de7c622379e04ad0097284926042;hpb=e52384426064bca0669a954736206adca7595d48;p=linux-2.6

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index f7263e104d..eab0327337 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -422,6 +422,7 @@ uart_get_divisor(struct uart_port *port, unsigned int baud)
 
 EXPORT_SYMBOL(uart_get_divisor);
 
+/* FIXME: Consistent locking policy */
 static void
 uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
 {
@@ -454,27 +455,30 @@ uart_change_speed(struct uart_state *state, struct ktermios *old_termios)
 	port->ops->set_termios(port, termios, old_termios);
 }
 
-static inline void
+static inline int
 __uart_put_char(struct uart_port *port, struct circ_buf *circ, unsigned char c)
 {
 	unsigned long flags;
+	int ret = 0;
 
 	if (!circ->buf)
-		return;
+		return 0;
 
 	spin_lock_irqsave(&port->lock, flags);
 	if (uart_circ_chars_free(circ) != 0) {
 		circ->buf[circ->head] = c;
 		circ->head = (circ->head + 1) & (UART_XMIT_SIZE - 1);
+		ret = 1;
 	}
 	spin_unlock_irqrestore(&port->lock, flags);
+	return ret;
 }
 
-static void uart_put_char(struct tty_struct *tty, unsigned char ch)
+static int uart_put_char(struct tty_struct *tty, unsigned char ch)
 {
 	struct uart_state *state = tty->driver_data;
 
-	__uart_put_char(state->port, &state->info->xmit, ch);
+	return __uart_put_char(state->port, &state->info->xmit, ch);
 }
 
 static void uart_flush_chars(struct tty_struct *tty)
@@ -528,21 +532,31 @@ uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
 static int uart_write_room(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
+	unsigned long flags;
+	int ret;
 
-	return uart_circ_chars_free(&state->info->xmit);
+	spin_lock_irqsave(&state->port->lock, flags);
+	ret = uart_circ_chars_free(&state->info->xmit);
+	spin_unlock_irqrestore(&state->port->lock, flags);
+	return ret;
 }
 
 static int uart_chars_in_buffer(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
+	unsigned long flags;
+	int ret;
 
-	return uart_circ_chars_pending(&state->info->xmit);
+	spin_lock_irqsave(&state->port->lock, flags);
+	ret = uart_circ_chars_pending(&state->info->xmit);
+	spin_unlock_irqrestore(&state->port->lock, flags);
+	return ret;
 }
 
 static void uart_flush_buffer(struct tty_struct *tty)
 {
 	struct uart_state *state = tty->driver_data;
-	struct uart_port *port = state->port;
+	struct uart_port *port;
 	unsigned long flags;
 
 	/*
@@ -554,6 +568,7 @@ static void uart_flush_buffer(struct tty_struct *tty)
 		return;
 	}
 
+	port = state->port;
 	pr_debug("uart_flush_buffer(%d) called\n", tty->index);
 
 	spin_lock_irqsave(&port->lock, flags);
@@ -618,6 +633,11 @@ static int uart_get_info(struct uart_state *state,
 	struct serial_struct tmp;
 
 	memset(&tmp, 0, sizeof(tmp));
+
+	/* Ensure the state we copy is consistent and no hardware changes
+	   occur as we go */
+	mutex_lock(&state->mutex);
+
 	tmp.type	    = port->type;
 	tmp.line	    = port->line;
 	tmp.port	    = port->iobase;
@@ -637,6 +657,8 @@ static int uart_get_info(struct uart_state *state,
 	tmp.iomem_reg_shift = port->regshift;
 	tmp.iomem_base      = (void *)(unsigned long)port->mapbase;
 
+	mutex_unlock(&state->mutex);
+
 	if (copy_to_user(retinfo, &tmp, sizeof(*retinfo)))
 		return -EFAULT;
 	return 0;
@@ -914,14 +936,12 @@ static void uart_break_ctl(struct tty_struct *tty, int break_state)
 	struct uart_state *state = tty->driver_data;
 	struct uart_port *port = state->port;
 
-	lock_kernel();
 	mutex_lock(&state->mutex);
 
 	if (port->type != PORT_UNKNOWN)
 		port->ops->break_ctl(port, break_state);
 
 	mutex_unlock(&state->mutex);
-	unlock_kernel();
 }
 
 static int uart_do_autoconfig(struct uart_state *state)
@@ -1070,7 +1090,6 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
 	int ret = -ENOIOCTLCMD;
 
 
-	lock_kernel();
 	/*
 	 * These ioctls don't rely on the hardware to be present.
 	 */
@@ -1140,10 +1159,9 @@ uart_ioctl(struct tty_struct *tty, struct file *filp, unsigned int cmd,
 		break;
 	}
 	}
- out_up:
+out_up:
 	mutex_unlock(&state->mutex);
- out:
-	unlock_kernel();
+out:
 	return ret;
 }
 
@@ -1169,7 +1187,6 @@ static void uart_set_termios(struct tty_struct *tty,
 		return;
 	}
 
-	lock_kernel();
 	uart_change_speed(state, old_termios);
 
 	/* Handle transition to B0 status */
@@ -1202,7 +1219,6 @@ static void uart_set_termios(struct tty_struct *tty,
 		}
 		spin_unlock_irqrestore(&state->port->lock, flags);
 	}
-	unlock_kernel();
 #if 0
 	/*
 	 * No need to wake up processes in open wait, since they
@@ -1318,11 +1334,11 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
 	struct uart_port *port = state->port;
 	unsigned long char_time, expire;
 
-	BUG_ON(!kernel_locked());
-
 	if (port->type == PORT_UNKNOWN || port->fifosize == 0)
 		return;
 
+	lock_kernel();
+
 	/*
 	 * Set the check interval to be 1/5 of the estimated time to
 	 * send a single character, and make it at least 1.  The check
@@ -1368,6 +1384,7 @@ static void uart_wait_until_sent(struct tty_struct *tty, int timeout)
 			break;
 	}
 	set_current_state(TASK_RUNNING); /* might not be needed */
+	unlock_kernel();
 }
 
 /*
@@ -2081,7 +2098,9 @@ int uart_resume_port(struct uart_driver *drv, struct uart_port *port)
 		int ret;
 
 		uart_change_pm(state, 0);
+		spin_lock_irq(&port->lock);
 		ops->set_mctrl(port, 0);
+		spin_unlock_irq(&port->lock);
 		ret = ops->startup(port);
 		if (ret == 0) {
 			uart_change_speed(state, NULL);