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_edgeport.c b/drivers/usb/serial/io_edgeport.c
index bfa508d..611f97f 100644
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -600,6 +600,7 @@
struct edgeport_serial *edge_serial = urb->context;
struct edgeport_port *edge_port;
struct usb_serial_port *port;
+ struct tty_struct *tty;
unsigned char *data = urb->transfer_buffer;
int length = urb->actual_length;
int bytes_avail;
@@ -675,9 +676,12 @@
/* tell the tty driver that something
has changed */
- if (edge_port->port->port.tty)
- tty_wakeup(edge_port->port->port.tty);
-
+ tty = tty_port_tty_get(
+ &edge_port->port->port);
+ if (tty) {
+ tty_wakeup(tty);
+ tty_kref_put(tty);
+ }
/* Since we have more credit, check
if more data can be sent */
send_more_port_data(edge_serial,
@@ -778,13 +782,14 @@
__func__, status);
}
- tty = edge_port->port->port.tty;
+ tty = tty_port_tty_get(&edge_port->port->port);
if (tty && edge_port->open) {
/* let the tty driver wakeup if it has a special
write_wakeup function */
tty_wakeup(tty);
}
+ tty_kref_put(tty);
/* Release the Write URB */
edge_port->write_in_progress = false;
@@ -826,11 +831,12 @@
}
/* Get pointer to tty */
- tty = edge_port->port->port.tty;
+ tty = tty_port_tty_get(&edge_port->port->port);
/* tell the tty driver that something has changed */
if (tty && edge_port->open)
tty_wakeup(tty);
+ tty_kref_put(tty);
/* we have completed the command */
edge_port->commandPending = false;
@@ -1932,11 +1938,13 @@
edge_serial->rxPort];
edge_port = usb_get_serial_port_data(port);
if (edge_port->open) {
- tty = edge_port->port->port.tty;
+ tty = tty_port_tty_get(
+ &edge_port->port->port);
if (tty) {
dbg("%s - Sending %d bytes to TTY for port %d",
__func__, rxLen, edge_serial->rxPort);
edge_tty_recv(&edge_serial->serial->dev->dev, tty, buffer, rxLen);
+ tty_kref_put(tty);
}
edge_port->icount.rx += rxLen;
}
@@ -1971,6 +1979,7 @@
{
struct usb_serial_port *port;
struct edgeport_port *edge_port;
+ struct tty_struct *tty;
__u8 code = edge_serial->rxStatusCode;
/* switch the port pointer to the one being currently talked about */
@@ -2020,10 +2029,12 @@
/* send the current line settings to the port so we are
in sync with any further termios calls */
- /* FIXME: locking on tty */
- if (edge_port->port->port.tty)
- change_port_settings(edge_port->port->port.tty,
- edge_port, edge_port->port->port.tty->termios);
+ tty = tty_port_tty_get(&edge_port->port->port);
+ if (tty) {
+ change_port_settings(tty,
+ edge_port, tty->termios);
+ tty_kref_put(tty);
+ }
/* we have completed the open */
edge_port->openPending = false;
@@ -2163,10 +2174,14 @@
}
/* Place LSR data byte into Rx buffer */
- if (lsrData && edge_port->port->port.tty)
- edge_tty_recv(&edge_port->port->dev,
- edge_port->port->port.tty, &data, 1);
-
+ if (lsrData) {
+ struct tty_struct *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;
if (newLsr & LSR_BREAK)