Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6

[linux-2.6] / drivers / serial / serial_core.c

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index f7263e104d81de7c622379e04ad0097284926042..eab032733790d5524ac9f14e8596c1a5a62e462c 100644 (file)
--- 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);