5 files changed, 55 insertions, 34 deletions

diff --git a/drivers/tty/serial/8250/8250_core.c b/drivers/tty/serial/8250/8250_core.c
index 81f909c2101f..0e1bf8858431 100644
--- a/drivers/tty/serial/8250/8250_core.c
+++ b/drivers/tty/serial/8250/8250_core.c
@@ -1520,7 +1520,7 @@ int serial8250_handle_irq(struct uart_port *port, unsigned int iir)
                         status = serial8250_rx_chars(up, status);
         }
         serial8250_modem_status(up);
-        if (status & UART_LSR_THRE)
+        if (!up->dma && (status & UART_LSR_THRE))
                 serial8250_tx_chars(up);
 
         spin_unlock_irqrestore(&port->lock, flags);
diff --git a/drivers/tty/serial/8250/8250_dma.c b/drivers/tty/serial/8250/8250_dma.c
index 7046769608d4..ab9096dc3849 100644
--- a/drivers/tty/serial/8250/8250_dma.c
+++ b/drivers/tty/serial/8250/8250_dma.c
@@ -20,12 +20,15 @@ static void __dma_tx_complete(void *param)
         struct uart_8250_port   *p = param;
         struct uart_8250_dma    *dma = p->dma;
         struct circ_buf         *xmit = &p->port.state->xmit;
-
-        dma->tx_running = 0;
+        unsigned long   flags;
 
         dma_sync_single_for_cpu(dma->txchan->device->dev, dma->tx_addr,
                                 UART_XMIT_SIZE, DMA_TO_DEVICE);
 
+        spin_lock_irqsave(&p->port.lock, flags);
+
+        dma->tx_running = 0;
+
         xmit->tail += dma->tx_size;
         xmit->tail &= UART_XMIT_SIZE - 1;
         p->port.icount.tx += dma->tx_size;
@@ -35,6 +38,8 @@ static void __dma_tx_complete(void *param)
 
         if (!uart_circ_empty(xmit) && !uart_tx_stopped(&p->port))
                 serial8250_tx_dma(p);
+
+        spin_unlock_irqrestore(&p->port.lock, flags);
 }
 
 static void __dma_rx_complete(void *param)
diff --git a/drivers/tty/serial/samsung.c b/drivers/tty/serial/samsung.c
index 23f459600738..1f5505e7f90d 100644
--- a/drivers/tty/serial/samsung.c
+++ b/drivers/tty/serial/samsung.c
@@ -1446,8 +1446,8 @@ static int s3c24xx_serial_get_poll_char(struct uart_port *port)
 static void s3c24xx_serial_put_poll_char(struct uart_port *port,
                 unsigned char c)
 {
-        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
-        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
+        unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
+        unsigned int ucon = rd_regl(port, S3C2410_UCON);
 
         /* not possible to xmit on unconfigured port */
         if (!s3c24xx_port_configured(ucon))
@@ -1455,7 +1455,7 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 
         while (!s3c24xx_serial_console_txrdy(port, ufcon))
                 cpu_relax();
-        wr_regb(cons_uart, S3C2410_UTXH, c);
+        wr_regb(port, S3C2410_UTXH, c);
 }
 
 #endif /* CONFIG_CONSOLE_POLL */
@@ -1463,22 +1463,23 @@ static void s3c24xx_serial_put_poll_char(struct uart_port *port,
 static void
 s3c24xx_serial_console_putchar(struct uart_port *port, int ch)
 {
-        unsigned int ufcon = rd_regl(cons_uart, S3C2410_UFCON);
-        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
-
-        /* not possible to xmit on unconfigured port */
-        if (!s3c24xx_port_configured(ucon))
-                return;
+        unsigned int ufcon = rd_regl(port, S3C2410_UFCON);
 
         while (!s3c24xx_serial_console_txrdy(port, ufcon))
-                barrier();
-        wr_regb(cons_uart, S3C2410_UTXH, ch);
+                cpu_relax();
+        wr_regb(port, S3C2410_UTXH, ch);
 }
 
 static void
 s3c24xx_serial_console_write(struct console *co, const char *s,
                              unsigned int count)
 {
+        unsigned int ucon = rd_regl(cons_uart, S3C2410_UCON);
+
+        /* not possible to xmit on unconfigured port */
+        if (!s3c24xx_port_configured(ucon))
+                return;
+
         uart_console_write(cons_uart, s, count, s3c24xx_serial_console_putchar);
 }
 
diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index f26834d262b3..b68550d95a40 100644
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -137,6 +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.
          */
@@ -825,25 +830,29 @@ 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;
                 }
@@ -1571,12 +1580,6 @@ 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);
diff --git a/drivers/tty/tty_buffer.c b/drivers/tty/tty_buffer.c
index 8ebd9f88a6f6..f1d30f6945af 100644
--- a/drivers/tty/tty_buffer.c
+++ b/drivers/tty/tty_buffer.c
@@ -255,11 +255,16 @@ static int __tty_buffer_request_room(struct tty_port *port, size_t size,
         if (change || left < size) {
                 /* This is the slow path - looking for new buffers to use */
                 if ((n = tty_buffer_alloc(port, size)) != NULL) {
+                        unsigned long iflags;
+
                         n->flags = flags;
                         buf->tail = n;
+
+                        spin_lock_irqsave(&buf->flush_lock, iflags);
                         b->commit = b->used;
-                        smp_mb();
                         b->next = n;
+                        spin_unlock_irqrestore(&buf->flush_lock, iflags);
+
                 } else if (change)
                         size = 0;
                 else
@@ -443,6 +448,7 @@ static void flush_to_ldisc(struct work_struct *work)
         mutex_lock(&buf->lock);
 
         while (1) {
+                unsigned long flags;
                 struct tty_buffer *head = buf->head;
                 int count;
 
@@ -450,14 +456,19 @@ static void flush_to_ldisc(struct work_struct *work)
                 if (atomic_read(&buf->priority))
                         break;
 
+                spin_lock_irqsave(&buf->flush_lock, flags);
                 count = head->commit - head->read;
                 if (!count) {
-                        if (head->next == NULL)
+                        if (head->next == NULL) {
+                                spin_unlock_irqrestore(&buf->flush_lock, flags);
                                 break;
+                        }
                         buf->head = head->next;
+                        spin_unlock_irqrestore(&buf->flush_lock, flags);
                         tty_buffer_free(port, head);
                         continue;
                 }
+                spin_unlock_irqrestore(&buf->flush_lock, flags);
 
                 count = receive_buf(tty, head, count);
                 if (!count)
@@ -512,6 +523,7 @@ void tty_buffer_init(struct tty_port *port)
         struct tty_bufhead *buf = &port->buf;
 
         mutex_init(&buf->lock);
+        spin_lock_init(&buf->flush_lock);
         tty_buffer_reset(&buf->sentinel, 0);
         buf->head = &buf->sentinel;
         buf->tail = &buf->sentinel;