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-rw-r--r--drivers/usb/serial/cypress_m8.c25
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 */