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/io_ti.c b/drivers/usb/serial/io_ti.c
index cb4c543..541dd8e 100644
--- a/drivers/usb/serial/io_ti.c
+++ b/drivers/usb/serial/io_ti.c
@@ -572,7 +572,7 @@
int flush)
{
int baud_rate;
- struct tty_struct *tty = port->port->port.tty;
+ struct tty_struct *tty = tty_port_tty_get(&port->port->port);
wait_queue_t wait;
unsigned long flags;
@@ -599,6 +599,7 @@
if (flush)
edge_buf_clear(port->ep_out_buf);
spin_unlock_irqrestore(&port->ep_lock, flags);
+ tty_kref_put(tty);
/* wait for data to drain from the device */
timeout += jiffies;
@@ -1554,7 +1555,7 @@
/* Save the new modem status */
edge_port->shadow_msr = msr & 0xf0;
- tty = edge_port->port->port.tty;
+ tty = tty_port_tty_get(&edge_port->port->port);
/* handle CTS flow control */
if (tty && C_CRTSCTS(tty)) {
if (msr & EDGEPORT_MSR_CTS) {
@@ -1564,6 +1565,7 @@
tty->hw_stopped = 1;
}
}
+ tty_kref_put(tty);
return;
}
@@ -1574,6 +1576,7 @@
struct async_icount *icount;
__u8 new_lsr = (__u8)(lsr & (__u8)(LSR_OVER_ERR | LSR_PAR_ERR |
LSR_FRM_ERR | LSR_BREAK));
+ struct tty_struct *tty;
dbg("%s - %02x", __func__, new_lsr);
@@ -1587,8 +1590,13 @@
new_lsr &= (__u8)(LSR_OVER_ERR | LSR_BREAK);
/* Place LSR data byte into Rx buffer */
- if (lsr_data && edge_port->port->port.tty)
- edge_tty_recv(&edge_port->port->dev, edge_port->port->port.tty, &data, 1);
+ if (lsr_data) {
+ tty = tty_port_tty_get(&edge_port->port->port);
+ if (tty) {
+ edge_tty_recv(&edge_port->port->dev, tty, &data, 1);
+ tty_kref_put(tty);
+ }
+ }
/* update input line counters */
icount = &edge_port->icount;
@@ -1749,7 +1757,7 @@
++data;
}
- tty = edge_port->port->port.tty;
+ tty = tty_port_tty_get(&edge_port->port->port);
if (tty && urb->actual_length) {
usb_serial_debug_data(debug, &edge_port->port->dev,
__func__, urb->actual_length, data);
@@ -1761,6 +1769,7 @@
urb->actual_length);
edge_port->icount.rx += urb->actual_length;
}
+ tty_kref_put(tty);
exit:
/* continue read unless stopped */
@@ -1796,6 +1805,7 @@
struct usb_serial_port *port = urb->context;
struct edgeport_port *edge_port = usb_get_serial_port_data(port);
int status = urb->status;
+ struct tty_struct *tty;
dbg("%s - port %d", __func__, port->number);
@@ -1818,7 +1828,9 @@
}
/* send any buffered data */
- edge_send(port->port.tty);
+ tty = tty_port_tty_get(&port->port);
+ edge_send(tty);
+ tty_kref_put(tty);
}
static int edge_open(struct tty_struct *tty,
@@ -1876,7 +1888,7 @@
/* set up the port settings */
if (tty)
- edge_set_termios(tty, port, port->port.tty->termios);
+ edge_set_termios(tty, port, tty->termios);
/* open up the port */