4 files changed, 33 insertions, 11 deletions

diff --git a/drivers/serial/ioc4_serial.c b/drivers/serial/ioc4_serial.c
index f3763d2ccb86..a37579ce6d76 100644
--- a/drivers/serial/ioc4_serial.c
+++ b/drivers/serial/ioc4_serial.c
@@ -2301,7 +2301,6 @@ static void receive_chars(struct uart_port *the_port)
         int read_count, request_count = IOC4_MAX_CHARS;
         struct uart_icount *icount;
         struct uart_info *info = the_port->info;
-        int flip = 0;
         unsigned long pflags;
 
         /* Make sure all the pointers are "good" ones */
@@ -2313,7 +2312,7 @@ static void receive_chars(struct uart_port *the_port)
         spin_lock_irqsave(&the_port->lock, pflags);
         tty = info->tty;
 
-        request_count = tty_buffer_request_room(tty, IOC4_MAX_CHARS - 2);
+        request_count = tty_buffer_request_room(tty, IOC4_MAX_CHARS);
 
         if (request_count > 0) {
                 icount = &the_port->icount;
@@ -2326,8 +2325,7 @@ static void receive_chars(struct uart_port *the_port)
 
         spin_unlock_irqrestore(&the_port->lock, pflags);
 
-        if (flip)
-                tty_flip_buffer_push(tty);
+        tty_flip_buffer_push(tty);
 }
 
 /**
diff --git a/drivers/serial/ip22zilog.c b/drivers/serial/ip22zilog.c
index 419dd3cd7862..193722d680cf 100644
--- a/drivers/serial/ip22zilog.c
+++ b/drivers/serial/ip22zilog.c
@@ -420,10 +420,8 @@ static void ip22zilog_transmit_chars(struct uart_ip22zilog_port *up,
         if (up->port.info == NULL)
                 goto ack_tx_int;
         xmit = &up->port.info->xmit;
-        if (uart_circ_empty(xmit)) {
-                uart_write_wakeup(&up->port);
+        if (uart_circ_empty(xmit))
                 goto ack_tx_int;
-        }
         if (uart_tx_stopped(&up->port))
                 goto ack_tx_int;
 
diff --git a/drivers/serial/serial_core.c b/drivers/serial/serial_core.c
index 95fb4939c675..cc1faa31d124 100644
--- a/drivers/serial/serial_core.c
+++ b/drivers/serial/serial_core.c
@@ -71,6 +71,11 @@ static void uart_change_pm(struct uart_state *state, int pm_state);
 void uart_write_wakeup(struct uart_port *port)
 {
         struct uart_info *info = port->info;
+        /*
+         * This means you called this function _after_ the port was
+         * closed.  No cookie for you.
+         */
+        BUG_ON(!info);
         tasklet_schedule(&info->tlet);
 }
 
@@ -471,14 +476,26 @@ static void uart_flush_chars(struct tty_struct *tty)
 }
 
 static int
-uart_write(struct tty_struct *tty, const unsigned char * buf, int count)
+uart_write(struct tty_struct *tty, const unsigned char *buf, int count)
 {
         struct uart_state *state = tty->driver_data;
-        struct uart_port *port = state->port;
-        struct circ_buf *circ = &state->info->xmit;
+        struct uart_port *port;
+        struct circ_buf *circ;
         unsigned long flags;
         int c, ret = 0;
 
+        /*
+         * This means you called this function _after_ the port was
+         * closed.  No cookie for you.
+         */
+        if (!state || !state->info) {
+                WARN_ON(1);
+                return -EL3HLT;
+        }
+
+        port = state->port;
+        circ = &state->info->xmit;
+
         if (!circ->buf)
                 return 0;
 
@@ -521,6 +538,15 @@ static void uart_flush_buffer(struct tty_struct *tty)
         struct uart_port *port = state->port;
         unsigned long flags;
 
+        /*
+         * This means you called this function _after_ the port was
+         * closed.  No cookie for you.
+         */
+        if (!state || !state->info) {
+                WARN_ON(1);
+                return;
+        }
+
         DPRINTK("uart_flush_buffer(%d) called\n", tty->index);
 
         spin_lock_irqsave(&port->lock, flags);
diff --git a/drivers/serial/sn_console.c b/drivers/serial/sn_console.c
index 43e67d6c29d4..60ea4a3f0713 100644
--- a/drivers/serial/sn_console.c
+++ b/drivers/serial/sn_console.c
@@ -820,7 +820,7 @@ static int __init sn_sal_module_init(void)
         int retval;
 
         if (!ia64_platform_is("sn2"))
-                return -ENODEV;
+                return 0;
 
         printk(KERN_INFO "sn_console: Console driver init\n");