From oneukum@suse.de Mon May 7 01:37:08 2007 From: Oliver Neukum Date: Mon, 7 May 2007 10:37:08 +0200 Subject: USB: visor driver adapted to new tty buffering To: "Greg Kroah-Hartman" , linux-usb-devel@lists.sourceforge.net Message-ID: <200705071037.08785.oneukum@suse.de> Content-Disposition: inline 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 Signed-off-by: Greg Kroah-Hartman --- drivers/usb/serial/visor.c | 30 ++++++++++++++++++------------ 1 file changed, 18 insertions(+), 12 deletions(-) --- a/drivers/usb/serial/visor.c +++ b/drivers/usb/serial/visor.c @@ -273,7 +273,8 @@ struct visor_private { 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 @@ static void visor_read_bulk_callback (st 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 @@ static void visor_read_bulk_callback (st 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 @@ static void visor_read_bulk_callback (st 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 @@ static void visor_unthrottle (struct usb 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;