diff options
| -rw-r--r-- | drivers/usb/serial/cypress_m8.c | 25 |
1 files changed, 16 insertions, 9 deletions
diff --git a/drivers/usb/serial/cypress_m8.c b/drivers/usb/serial/cypress_m8.c index 163386336a5..08c65c1a377 100644 --- a/drivers/usb/serial/cypress_m8.c +++ b/drivers/usb/serial/cypress_m8.c @@ -682,7 +682,6 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp) { struct cypress_private *priv = usb_get_serial_port_data(port); unsigned int c_cflag; - unsigned long flags; int bps; long timeout; wait_queue_t wait; @@ -690,7 +689,7 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp) dbg("%s - port %d", __FUNCTION__, port->number); /* wait for data to drain from buffer */ - spin_lock_irqsave(&priv->lock, flags); + spin_lock_irq(&priv->lock); timeout = CYPRESS_CLOSING_WAIT; init_waitqueue_entry(&wait, current); add_wait_queue(&port->tty->write_wait, &wait); @@ -698,18 +697,25 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp) set_current_state(TASK_INTERRUPTIBLE); if (cypress_buf_data_avail(priv->buf) == 0 || timeout == 0 || signal_pending(current) - || !usb_get_intfdata(port->serial->interface)) + /* without mutex, allowed due to harmless failure mode */ + || port->serial->disconnected) break; - spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irq(&priv->lock); timeout = schedule_timeout(timeout); - spin_lock_irqsave(&priv->lock, flags); + spin_lock_irq(&priv->lock); } set_current_state(TASK_RUNNING); remove_wait_queue(&port->tty->write_wait, &wait); /* clear out any remaining data in the buffer */ cypress_buf_clear(priv->buf); - spin_unlock_irqrestore(&priv->lock, flags); - + spin_unlock_irq(&priv->lock); + + /* writing is potentially harmful, lock must be taken */ + mutex_lock(&port->serial->disc_mutex); + if (port->serial->disconnected) { + mutex_unlock(&port->serial->disc_mutex); + return; + } /* wait for characters to drain from device */ bps = tty_get_baud_rate(port->tty); if (bps > 1200) @@ -727,10 +733,10 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp) if (c_cflag & HUPCL) { /* drop dtr and rts */ priv = usb_get_serial_port_data(port); - spin_lock_irqsave(&priv->lock, flags); + spin_lock_irq(&priv->lock); priv->line_control = 0; priv->cmd_ctrl = 1; - spin_unlock_irqrestore(&priv->lock, flags); + spin_unlock_irq(&priv->lock); cypress_write(port, NULL, 0); } } @@ -738,6 +744,7 @@ static void cypress_close(struct usb_serial_port *port, struct file * filp) if (stats) dev_info (&port->dev, "Statistics: %d Bytes In | %d Bytes Out | %d Commands Issued\n", priv->bytes_in, priv->bytes_out, priv->cmd_count); + mutex_unlock(&port->serial->disc_mutex); } /* cypress_close */ |