USB: serial: fix generic chars_in_buffer
Make sure chars_in_buffer accounts also for data in host stack queues.
This fixes the problem with tty_wait_until_sent returning too soon at
close which could cause the final write urb to be cancelled.
Reported-by: Pete Zaitcev <zaitcev@redhat.com>
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/generic.c b/drivers/usb/serial/generic.c
index a5e6109..8f78d7b 100644
--- a/drivers/usb/serial/generic.c
+++ b/drivers/usb/serial/generic.c
@@ -309,10 +309,14 @@
/* don't have to grab the lock here, as we will
retry if != 0 */
port->write_urb_busy = 0;
- } else
- result = count;
+ return result;
+ }
- return result;
+ spin_lock_irqsave(&port->lock, flags);
+ port->tx_bytes_flight += count;
+ spin_unlock_irqrestore(&port->lock, flags);
+
+ return count;
}
/**
@@ -400,7 +404,7 @@
if (serial->type->max_in_flight_urbs)
chars = port->tx_bytes_flight;
else
- chars = kfifo_len(&port->write_fifo);
+ chars = kfifo_len(&port->write_fifo) + port->tx_bytes_flight;
spin_unlock_irqrestore(&port->lock, flags);
dbg("%s - returns %d", __func__, chars);
@@ -510,7 +514,10 @@
port->urbs_in_flight = 0;
spin_unlock_irqrestore(&port->lock, flags);
} else {
+ spin_lock_irqsave(&port->lock, flags);
+ port->tx_bytes_flight -= urb->transfer_buffer_length;
port->write_urb_busy = 0;
+ spin_unlock_irqrestore(&port->lock, flags);
if (status)
kfifo_reset_out(&port->write_fifo);