From: Oliver Neukum <[EMAIL PROTECTED]>
the generic driver also had its own buffering.
Signed-off-by: Oliver Neukum <[EMAIL PROTECTED]
Signed-off-by: Greg Kroah-Hartman <[EMAIL PROTECTED]>
---
drivers/usb/serial/generic.c | 69 ++++++++++++++++++++---------------------
1 files changed, 34 insertions(+), 35 deletions(-)
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index b90ef3f..b09bed4 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -281,45 +281,54 @@ int usb_serial_generic_chars_in_buffer (struct
usb_serial_port *port)
return (chars);
}
-/* Push data to tty layer and resubmit the bulk read URB */
-static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
+
+static void resubmit_read_urb(struct usb_serial_port *port, gfp_t mem_flags)
{
- struct usb_serial *serial = port->serial;
struct urb *urb = port->read_urb;
- struct tty_struct *tty = port->tty;
+ struct usb_serial *serial = port->serial;
int result;
- /* Push data to tty */
- if (tty && urb->actual_length) {
- tty_buffer_request_room(tty, urb->actual_length);
- tty_insert_flip_string(tty, urb->transfer_buffer,
urb->actual_length);
- tty_flip_buffer_push(tty); /* is this allowed from an URB
callback ? */
- }
-
/* Continue reading from device */
- usb_fill_bulk_urb (port->read_urb, serial->dev,
+ usb_fill_bulk_urb (urb, serial->dev,
usb_rcvbulkpipe (serial->dev,
port->bulk_in_endpointAddress),
- port->read_urb->transfer_buffer,
- port->read_urb->transfer_buffer_length,
+ urb->transfer_buffer,
+ urb->transfer_buffer_length,
((serial->type->read_bulk_callback) ?
serial->type->read_bulk_callback :
usb_serial_generic_read_bulk_callback), port);
- result = usb_submit_urb(port->read_urb, GFP_ATOMIC);
+ result = usb_submit_urb(urb, mem_flags);
if (result)
dev_err(&port->dev, "%s - failed resubmitting read urb, error
%d\n", __FUNCTION__, result);
}
+/* Push data to tty layer and resubmit the bulk read URB */
+static void flush_and_resubmit_read_urb (struct usb_serial_port *port)
+{
+ struct urb *urb = port->read_urb;
+ struct tty_struct *tty = port->tty;
+ int room;
+
+ /* Push data to tty */
+ if (tty && urb->actual_length) {
+ room = tty_buffer_request_room(tty, urb->actual_length);
+ if (room) {
+ tty_insert_flip_string(tty, urb->transfer_buffer, room);
+ tty_flip_buffer_push(tty); /* is this allowed from an
URB callback ? */
+ }
+ }
+
+ resubmit_read_urb(port, GFP_ATOMIC);
+}
+
void usb_serial_generic_read_bulk_callback (struct urb *urb)
{
struct usb_serial_port *port = (struct usb_serial_port *)urb->context;
unsigned char *data = urb->transfer_buffer;
- int is_throttled;
- unsigned long flags;
dbg("%s - port %d", __FUNCTION__, port->number);
- if (urb->status) {
+ if (unlikely(urb->status != 0)) {
dbg("%s - nonzero read bulk status received: %d", __FUNCTION__,
urb->status);
return;
}
@@ -327,21 +336,11 @@ void usb_serial_generic_read_bulk_callback (struct urb
*urb)
usb_serial_debug_data(debug, &port->dev, __FUNCTION__,
urb->actual_length, data);
/* Throttle the device if requested by tty */
- if (urb->actual_length) {
- spin_lock_irqsave(&port->lock, flags);
- is_throttled = port->throttled = port->throttle_req;
- spin_unlock_irqrestore(&port->lock, flags);
- if (is_throttled) {
- /* Let the received data linger in the read URB;
- * usb_serial_generic_unthrottle() will pick it
- * up later. */
- dbg("%s - throttling device", __FUNCTION__);
- return;
- }
- }
-
- /* Handle data and continue reading from device */
- flush_and_resubmit_read_urb(port);
+ spin_lock(&port->lock);
+ if (!(port->throttled = port->throttle_req))
+ /* Handle data and continue reading from device */
+ flush_and_resubmit_read_urb(port);
+ spin_unlock(&port->lock);
}
EXPORT_SYMBOL_GPL(usb_serial_generic_read_bulk_callback);
@@ -388,8 +387,8 @@ void usb_serial_generic_unthrottle (struct usb_serial_port
*port)
spin_unlock_irqrestore(&port->lock, flags);
if (was_throttled) {
- /* Handle pending data and resume reading from device */
- flush_and_resubmit_read_urb(port);
+ /* Resume reading from device */
+ resubmit_read_urb(port, GFP_KERNEL);
}
}
--
1.5.2.2
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