tty: usb-serial krefs
Use kref in the USB serial drivers so that we don't free tty structures
from under the URB receive handlers as has historically been the case if
you were unlucky. This also gives us a framework for general tty drivers to
use tty_port objects and refcount.
Contains two err->dev_err changes merged together to fix clashes in the
-next tree.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/usb/serial/digi_acceleport.c b/drivers/usb/serial/digi_acceleport.c
index 240aad1..5756ac6 100644
--- a/drivers/usb/serial/digi_acceleport.c
+++ b/drivers/usb/serial/digi_acceleport.c
@@ -604,7 +604,9 @@
static void digi_wakeup_write(struct usb_serial_port *port)
{
- tty_wakeup(port->port.tty);
+ struct tty_struct *tty = tty_port_tty_get(&port->port);
+ tty_wakeup(tty);
+ tty_kref_put(tty);
}
@@ -1668,7 +1670,7 @@
{
struct usb_serial_port *port = urb->context;
- struct tty_struct *tty = port->port.tty;
+ struct tty_struct *tty;
struct digi_port *priv = usb_get_serial_port_data(port);
int opcode = ((unsigned char *)urb->transfer_buffer)[0];
int len = ((unsigned char *)urb->transfer_buffer)[1];
@@ -1692,6 +1694,7 @@
return -1;
}
+ tty = tty_port_tty_get(&port->port);
spin_lock(&priv->dp_port_lock);
/* check for throttle; if set, do not resubmit read urb */
@@ -1735,6 +1738,7 @@
}
}
spin_unlock(&priv->dp_port_lock);
+ tty_kref_put(tty);
if (opcode == DIGI_CMD_RECEIVE_DISABLE)
dbg("%s: got RECEIVE_DISABLE", __func__);
@@ -1760,6 +1764,7 @@
struct usb_serial_port *port = urb->context;
struct usb_serial *serial = port->serial;
+ struct tty_struct *tty;
struct digi_port *priv = usb_get_serial_port_data(port);
int opcode, line, status, val;
int i;
@@ -1787,10 +1792,11 @@
if (priv == NULL)
return -1;
+ tty = tty_port_tty_get(&port->port);
rts = 0;
if (port->port.count)
- rts = port->port.tty->termios->c_cflag & CRTSCTS;
-
+ rts = tty->termios->c_cflag & CRTSCTS;
+
if (opcode == DIGI_CMD_READ_INPUT_SIGNALS) {
spin_lock(&priv->dp_port_lock);
/* convert from digi flags to termiox flags */
@@ -1798,14 +1804,14 @@
priv->dp_modem_signals |= TIOCM_CTS;
/* port must be open to use tty struct */
if (rts) {
- port->port.tty->hw_stopped = 0;
+ tty->hw_stopped = 0;
digi_wakeup_write(port);
}
} else {
priv->dp_modem_signals &= ~TIOCM_CTS;
/* port must be open to use tty struct */
if (rts)
- port->port.tty->hw_stopped = 1;
+ tty->hw_stopped = 1;
}
if (val & DIGI_READ_INPUT_SIGNALS_DSR)
priv->dp_modem_signals |= TIOCM_DSR;
@@ -1830,6 +1836,7 @@
} else if (opcode == DIGI_CMD_IFLUSH_FIFO) {
wake_up_interruptible(&priv->dp_flush_wait);
}
+ tty_kref_put(tty);
}
return 0;