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authorOliver Neukum <oliver@neukum.org>2008-01-21 17:44:10 +0100
committerGreg Kroah-Hartman <gregkh@suse.de>2008-02-01 14:35:04 -0800
commite33fe4d86f91127f6f7d931ff59ed6cbda06e72b (patch)
tree7af352e8fc696220a06c6e2a9b9006a0ea5ee075 /drivers/usb/serial/mct_u232.c
parent004b4f2d4448cff7f13871c05d744b00a7c74d4a (diff)
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USB: make sure usb serial drivers don't flush to logically disconnected devices
If disconnect() is called for a logical disconnect, no more IO must be done after disconnect() returns, or the old and new drivers may conflict. This patch avoids this by using the flag and lock introduced by the earlier patch for the mos7720 driver. Signed-off-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers/usb/serial/mct_u232.c')
-rw-r--r--drivers/usb/serial/mct_u232.c17
1 files changed, 9 insertions, 8 deletions
diff --git a/drivers/usb/serial/mct_u232.c b/drivers/usb/serial/mct_u232.c
index 88b2074867c..fc1cea4aba1 100644
--- a/drivers/usb/serial/mct_u232.c
+++ b/drivers/usb/serial/mct_u232.c
@@ -487,21 +487,22 @@ error:
static void mct_u232_close (struct usb_serial_port *port, struct file *filp)
{
unsigned int c_cflag;
- unsigned long flags;
unsigned int control_state;
struct mct_u232_private *priv = usb_get_serial_port_data(port);
dbg("%s port %d", __FUNCTION__, port->number);
if (port->tty) {
c_cflag = port->tty->termios->c_cflag;
- if (c_cflag & HUPCL) {
- /* drop DTR and RTS */
- spin_lock_irqsave(&priv->lock, flags);
- priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
- control_state = priv->control_state;
- spin_unlock_irqrestore(&priv->lock, flags);
- mct_u232_set_modem_ctrl(port->serial, control_state);
+ mutex_lock(&port->serial->disc_mutex);
+ if (c_cflag & HUPCL && !port->serial->disconnected) {
+ /* drop DTR and RTS */
+ spin_lock_irq(&priv->lock);
+ priv->control_state &= ~(TIOCM_DTR | TIOCM_RTS);
+ control_state = priv->control_state;
+ spin_unlock_irq(&priv->lock);
+ mct_u232_set_modem_ctrl(port->serial, control_state);
}
+ mutex_unlock(&port->serial->disc_mutex);
}