USB: visor driver adapted to new tty buffering
the new tty buffering code allows usb drivers to stop private buffering.
In fact we must do so to allow flushing to work correctly. This does so
for the visor driver.
Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/visor.c b/drivers/usb/serial/visor.c
index ffbe601..ca826b9 100644
--- a/drivers/usb/serial/visor.c
+++ b/drivers/usb/serial/visor.c
@@ -273,7 +273,8 @@
int bytes_in;
int bytes_out;
int outstanding_urbs;
- int throttled;
+ unsigned char throttled;
+ unsigned char actually_throttled;
};
/* number of outstanding urbs to prevent userspace DoS from happening */
@@ -509,9 +510,8 @@
struct visor_private *priv = usb_get_serial_port_data(port);
unsigned char *data = urb->transfer_buffer;
struct tty_struct *tty;
- unsigned long flags;
- int throttled;
int result;
+ int available_room;
dbg("%s - port %d", __FUNCTION__, port->number);
@@ -524,17 +524,20 @@
tty = port->tty;
if (tty && 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);
+ available_room = tty_buffer_request_room(tty, urb->actual_length);
+ if (available_room) {
+ tty_insert_flip_string(tty, data, available_room);
+ tty_flip_buffer_push(tty);
+ }
+ spin_lock(&priv->lock);
+ priv->bytes_in += available_room;
+
+ } else {
+ spin_lock(&priv->lock);
}
- spin_lock_irqsave(&priv->lock, flags);
- priv->bytes_in += urb->actual_length;
- throttled = priv->throttled;
- spin_unlock_irqrestore(&priv->lock, flags);
/* Continue trying to always read if we should */
- if (!throttled) {
+ if (!priv->throttled) {
usb_fill_bulk_urb (port->read_urb, port->serial->dev,
usb_rcvbulkpipe(port->serial->dev,
port->bulk_in_endpointAddress),
@@ -544,8 +547,10 @@
result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
if (result)
dev_err(&port->dev, "%s - failed resubmitting read urb, error %d\n", __FUNCTION__, result);
+ } else {
+ priv->actually_throttled = 1;
}
- return;
+ spin_unlock(&priv->lock);
}
static void visor_read_int_callback (struct urb *urb)
@@ -608,6 +613,7 @@
dbg("%s - port %d", __FUNCTION__, port->number);
spin_lock_irqsave(&priv->lock, flags);
priv->throttled = 0;
+ priv->actually_throttled = 0;
spin_unlock_irqrestore(&priv->lock, flags);
port->read_urb->dev = port->serial->dev;