[PATCH] USB: new cp2101 device

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

diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index cc1faa3..17839e7 100644 (file)
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -1500,20 +1500,18 @@ uart_block_til_ready(struct file *filp, struct uart_state *state)
 static struct uart_state *uart_get(struct uart_driver *drv, int line)
 {
        struct uart_state *state;
+       int ret = 0;
 
-       mutex_lock(&port_mutex);
        state = drv->state + line;
        if (mutex_lock_interruptible(&state->mutex)) {
-               state = ERR_PTR(-ERESTARTSYS);
-               goto out;
+               ret = -ERESTARTSYS;
+               goto err;
        }
 
        state->count++;
-       if (!state->port) {
-               state->count--;
-               mutex_unlock(&state->mutex);
-               state = ERR_PTR(-ENXIO);
-               goto out;
+       if (!state->port || state->port->flags & UPF_DEAD) {
+               ret = -ENXIO;
+               goto err_unlock;
        }
 
        if (!state->info) {
@@ -1531,15 +1529,17 @@ static struct uart_state *uart_get(struct uart_driver *drv, int line)
                        tasklet_init(&state->info->tlet, uart_tasklet_action,
                                     (unsigned long)state);
                } else {
-                       state->count--;
-                       mutex_unlock(&state->mutex);
-                       state = ERR_PTR(-ENOMEM);
+                       ret = -ENOMEM;
+                       goto err_unlock;
                }
        }
-
- out:
-       mutex_unlock(&port_mutex);
        return state;
+
+ err_unlock:
+       state->count--;
+       mutex_unlock(&state->mutex);
+ err:
+       return ERR_PTR(ret);
 }
 
 /*
@@ -1755,6 +1755,27 @@ static int uart_read_proc(char *page, char **start, off_t off,
 
 #ifdef CONFIG_SERIAL_CORE_CONSOLE
 /*
+ *     uart_console_write - write a console message to a serial port
+ *     @port: the port to write the message
+ *     @s: array of characters
+ *     @count: number of characters in string to write
+ *     @write: function to write character to port
+ */
+void uart_console_write(struct uart_port *port, const char *s,
+                       unsigned int count,
+                       void (*putchar)(struct uart_port *, int))
+{
+       unsigned int i;
+
+       for (i = 0; i < count; i++, s++) {
+               if (*s == '\n')
+                       putchar(port, '\r');
+               putchar(port, *s);
+       }
+}
+EXPORT_SYMBOL_GPL(uart_console_write);
+
+/*
  *     Check whether an invalid uart number has been specified, and
  *     if so, search for the first available port that does have
  *     console support.
@@ -1886,9 +1907,12 @@ uart_set_options(struct uart_port *port, struct console *co,
 static void uart_change_pm(struct uart_state *state, int pm_state)
 {
        struct uart_port *port = state->port;
-       if (port->ops->pm)
-               port->ops->pm(port, pm_state, state->pm_state);
-       state->pm_state = pm_state;
+
+       if (state->pm_state != pm_state) {
+               if (port->ops->pm)
+                       port->ops->pm(port, pm_state, state->pm_state);
+               state->pm_state = pm_state;
+       }
 }
 
 int uart_suspend_port(struct uart_driver *drv, struct uart_port *port)
@@ -2064,45 +2088,6 @@ uart_configure_port(struct uart_driver *drv, struct uart_state *state,
        }
 }
 
-/*
- * This reverses the effects of uart_configure_port, hanging up the
- * port before removal.
- */
-static void
-uart_unconfigure_port(struct uart_driver *drv, struct uart_state *state)
-{
-       struct uart_port *port = state->port;
-       struct uart_info *info = state->info;
-
-       if (info && info->tty)
-               tty_vhangup(info->tty);
-
-       mutex_lock(&state->mutex);
-
-       state->info = NULL;
-
-       /*
-        * Free the port IO and memory resources, if any.
-        */
-       if (port->type != PORT_UNKNOWN)
-               port->ops->release_port(port);
-
-       /*
-        * Indicate that there isn't a port here anymore.
-        */
-       port->type = PORT_UNKNOWN;
-
-       /*
-        * Kill the tasklet, and free resources.
-        */
-       if (info) {
-               tasklet_kill(&info->tlet);
-               kfree(info);
-       }
-
-       mutex_unlock(&state->mutex);
-}
-
 static struct tty_operations uart_ops = {
        .open           = uart_open,
        .close          = uart_close,
@@ -2249,6 +2234,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
        state = drv->state + port->line;
 
        mutex_lock(&port_mutex);
+       mutex_lock(&state->mutex);
        if (state->port) {
                ret = -EINVAL;
                goto out;
@@ -2283,7 +2269,13 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
            port->cons && !(port->cons->flags & CON_ENABLED))
                register_console(port->cons);
 
+       /*
+        * Ensure UPF_DEAD is not set.
+        */
+       port->flags &= ~UPF_DEAD;
+
  out:
+       mutex_unlock(&state->mutex);
        mutex_unlock(&port_mutex);
 
        return ret;
@@ -2301,6 +2293,7 @@ int uart_add_one_port(struct uart_driver *drv, struct uart_port *port)
 int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
 {
        struct uart_state *state = drv->state + port->line;
+       struct uart_info *info;
 
        BUG_ON(in_interrupt());
 
@@ -2311,11 +2304,48 @@ int uart_remove_one_port(struct uart_driver *drv, struct uart_port *port)
        mutex_lock(&port_mutex);
 
        /*
+        * Mark the port "dead" - this prevents any opens from
+        * succeeding while we shut down the port.
+        */
+       mutex_lock(&state->mutex);
+       port->flags |= UPF_DEAD;
+       mutex_unlock(&state->mutex);
+
+       /*
         * Remove the devices from devfs
         */
        tty_unregister_device(drv->tty_driver, port->line);
 
-       uart_unconfigure_port(drv, state);
+       info = state->info;
+       if (info && info->tty)
+               tty_vhangup(info->tty);
+
+       /*
+        * All users of this port should now be disconnected from
+        * this driver, and the port shut down.  We should be the
+        * only thread fiddling with this port from now on.
+        */
+       state->info = NULL;
+
+       /*
+        * Free the port IO and memory resources, if any.
+        */
+       if (port->type != PORT_UNKNOWN)
+               port->ops->release_port(port);
+
+       /*
+        * Indicate that there isn't a port here anymore.
+        */
+       port->type = PORT_UNKNOWN;
+
+       /*
+        * Kill the tasklet, and free resources.
+        */
+       if (info) {
+               tasklet_kill(&info->tlet);
+               kfree(info);
+       }
+
        state->port = NULL;
        mutex_unlock(&port_mutex);