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/aircable.c b/drivers/usb/serial/aircable.c
index 79ea98c..99fb7dc 100644
--- a/drivers/usb/serial/aircable.c
+++ b/drivers/usb/serial/aircable.c
@@ -272,7 +272,7 @@
* 64 bytes, to ensure I do not get throttled.
* Ask USB mailing list for better aproach.
*/
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (!tty) {
schedule_work(&priv->rx_work);
@@ -283,12 +283,13 @@
count = min(64, serial_buf_data_avail(priv->rx_buf));
if (count <= 0)
- return; /* We have finished sending everything. */
+ goto out; /* We have finished sending everything. */
tty_prepare_flip_string(tty, &data, count);
if (!data) {
- err("%s- kzalloc(%d) failed.", __func__, count);
- return;
+ dev_err(&port->dev, "%s- kzalloc(%d) failed.",
+ __func__, count);
+ goto out;
}
serial_buf_get(priv->rx_buf, data, count);
@@ -297,7 +298,8 @@
if (serial_buf_data_avail(priv->rx_buf))
schedule_work(&priv->rx_work);
-
+out:
+ tty_kref_put(tty);
return;
}
/* End of private methods */
@@ -495,7 +497,7 @@
usb_serial_debug_data(debug, &port->dev, __func__,
urb->actual_length, urb->transfer_buffer);
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (tty && urb->actual_length) {
if (urb->actual_length <= 2) {
/* This is an incomplete package */
@@ -527,6 +529,7 @@
}
aircable_read(&priv->rx_work);
}
+ tty_kref_put(tty);
/* Schedule the next read _if_ we are still open */
if (port->port.count) {
