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/option.c b/drivers/usb/serial/option.c
index 73f8277..6b1727e 100644
--- a/drivers/usb/serial/option.c
+++ b/drivers/usb/serial/option.c
@@ -571,14 +571,14 @@
dbg("%s: nonzero status: %d on endpoint %02x.",
__func__, status, endpoint);
} else {
- tty = port->port.tty;
+ tty = tty_port_tty_get(&port->port);
if (urb->actual_length) {
tty_buffer_request_room(tty, urb->actual_length);
tty_insert_flip_string(tty, data, urb->actual_length);
tty_flip_buffer_push(tty);
- } else {
+ } else
dbg("%s: empty read urb received", __func__);
- }
+ tty_kref_put(tty);
/* Resubmit urb so we continue receiving */
if (port->port.count && status != -ESHUTDOWN) {
@@ -647,9 +647,13 @@
portdata->dsr_state = ((signals & 0x02) ? 1 : 0);
portdata->ri_state = ((signals & 0x08) ? 1 : 0);
- if (port->port.tty && !C_CLOCAL(port->port.tty) &&
- old_dcd_state && !portdata->dcd_state)
- tty_hangup(port->port.tty);
+ if (old_dcd_state && !portdata->dcd_state) {
+ struct tty_struct *tty =
+ tty_port_tty_get(&port->port);
+ if (tty && !C_CLOCAL(tty))
+ tty_hangup(tty);
+ tty_kref_put(tty);
+ }
} else {
dbg("%s: type %x req %x", __func__,
req_pkt->bRequestType, req_pkt->bRequest);
@@ -793,7 +797,7 @@
for (i = 0; i < N_OUT_URB; i++)
usb_kill_urb(portdata->out_urbs[i]);
}
- port->port.tty = NULL; /* FIXME */
+ tty_port_tty_set(&port->port, NULL);
}
/* Helper functions used by option_setup_urbs */