Make sure to wake up any process sleeping on the modem-status-change
queue at port remove.
Currently a process waiting on modem status changes will not
necessarily be woken on device disconnect.
Note that we need to use the disconnected flag to detect disconnect
as the port private data may have been freed when woken up.
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Johan Hovold <jhovold@xxxxxxxxx>
---
drivers/usb/serial/quatech2.c | 13 ++++++-------
1 file changed, 6 insertions(+), 7 deletions(-)
diff --git a/drivers/usb/serial/quatech2.c b/drivers/usb/serial/quatech2.c
index 00e6c9b..89709bd 100644
--- a/drivers/usb/serial/quatech2.c
+++ b/drivers/usb/serial/quatech2.c
@@ -507,7 +507,8 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
while (1) {
wait_event_interruptible(priv->delta_msr_wait,
- ((priv->icount.rng != prev.rng) ||
+ (port->serial->disconnected ||
+ (priv->icount.rng != prev.rng) ||
(priv->icount.dsr != prev.dsr) ||
(priv->icount.dcd != prev.dcd) ||
(priv->icount.cts != prev.cts)));
@@ -515,16 +516,13 @@ static int wait_modem_info(struct usb_serial_port *port, unsigned int arg)
if (signal_pending(current))
return -ERESTARTSYS;
+ if (port->serial->disconnected)
+ return -EIO;
+
spin_lock_irqsave(&priv->lock, flags);
cur = priv->icount;
spin_unlock_irqrestore(&priv->lock, flags);
- if ((prev.rng == cur.rng) &&
- (prev.dsr == cur.dsr) &&
- (prev.dcd == cur.dcd) &&
- (prev.cts == cur.cts))
- return -EIO;
-
if ((arg & TIOCM_RNG && (prev.rng != cur.rng)) ||
(arg & TIOCM_DSR && (prev.dsr != cur.dsr)) ||
(arg & TIOCM_CD && (prev.dcd != cur.dcd)) ||
@@ -849,6 +847,7 @@ static int qt2_port_remove(struct usb_serial_port *port)
struct qt2_port_private *port_priv;
port_priv = usb_get_serial_port_data(port);
+ wake_up_interruptible(&port_priv->delta_msr_wait);
usb_free_urb(port_priv->write_urb);
kfree(port_priv);
--
1.8.1.1
--
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