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 as wake_up was called from
dtr_rts which isn't guaranteed to be called (e.g. if HUPCL is not set).
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 <sta...@vger.kernel.org>
Signed-off-by: Johan Hovold <jhov...@gmail.com>
---
drivers/usb/serial/ch341.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/serial/ch341.c b/drivers/usb/serial/ch341.c
index d255f66..7acb155 100644
--- a/drivers/usb/serial/ch341.c
+++ b/drivers/usb/serial/ch341.c
@@ -271,6 +271,8 @@ static int ch341_port_remove(struct usb_serial_port *port)
{
struct ch341_private *priv;
+ wake_up_interruptible(&priv->delta_msr_wait);
+
priv = usb_get_serial_port_data(port);
kfree(priv);
@@ -298,7 +300,6 @@ static void ch341_dtr_rts(struct usb_serial_port *port, int
on)
priv->line_control &= ~(CH341_BIT_RTS | CH341_BIT_DTR);
spin_unlock_irqrestore(&priv->lock, flags);
ch341_set_handshake(port->serial->dev, priv->line_control);
- wake_up_interruptible(&priv->delta_msr_wait);
}
static void ch341_close(struct usb_serial_port *port)
@@ -522,6 +523,9 @@ 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);
status = priv->line_status;
multi_change = priv->multi_status_change;
--
1.8.1.1
--
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