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/ftdi_sio.c b/drivers/usb/serial/ftdi_sio.c
index 1ac7e80..c2ac129 100644
--- a/drivers/usb/serial/ftdi_sio.c
+++ b/drivers/usb/serial/ftdi_sio.c
@@ -1808,7 +1808,7 @@
if (port->port.count <= 0)
return;
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (!tty) {
dbg("%s - bad tty pointer - exiting", __func__);
return;
@@ -1817,7 +1817,7 @@
priv = usb_get_serial_port_data(port);
if (!priv) {
dbg("%s - bad port private data pointer - exiting", __func__);
- return;
+ goto out;
}
if (urb != port->read_urb)
@@ -1827,7 +1827,7 @@
/* This will happen at close every time so it is a dbg not an
err */
dbg("(this is ok on close) nonzero read bulk status received: %d", status);
- return;
+ goto out;
}
/* count data bytes, but not status bytes */
@@ -1838,7 +1838,8 @@
spin_unlock_irqrestore(&priv->rx_lock, flags);
ftdi_process_read(&priv->rx_work.work);
-
+out:
+ tty_kref_put(tty);
} /* ftdi_read_bulk_callback */
@@ -1863,7 +1864,7 @@
if (port->port.count <= 0)
return;
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (!tty) {
dbg("%s - bad tty pointer - exiting", __func__);
return;
@@ -1872,13 +1873,13 @@
priv = usb_get_serial_port_data(port);
if (!priv) {
dbg("%s - bad port private data pointer - exiting", __func__);
- return;
+ goto out;
}
urb = port->read_urb;
if (!urb) {
dbg("%s - bad read_urb pointer - exiting", __func__);
- return;
+ goto out;
}
data = urb->transfer_buffer;
@@ -2020,7 +2021,7 @@
schedule_delayed_work(&priv->rx_work, 1);
else
dbg("%s - port is closed", __func__);
- return;
+ goto out;
}
/* urb is completely processed */
@@ -2041,6 +2042,8 @@
err("%s - failed resubmitting read urb, error %d",
__func__, result);
}
+out:
+ tty_kref_put(tty);
} /* ftdi_process_read */