[PATCH] USB: add ability for usb-serial drivers to determine if their write urb is currently being used.
This removes a lot of racy and buggy code by trying to check the status of the urb.
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/serial/ipw.c b/drivers/usb/serial/ipw.c
index 11105d7..85e2424 100644
--- a/drivers/usb/serial/ipw.c
+++ b/drivers/usb/serial/ipw.c
@@ -399,16 +399,21 @@
dbg("%s - write request of 0 bytes", __FUNCTION__);
return 0;
}
-
- /* Racy and broken, FIXME properly! */
- if (port->write_urb->status == -EINPROGRESS)
+
+ spin_lock(&port->lock);
+ if (port->write_urb_busy) {
+ spin_unlock(&port->lock);
+ dbg("%s - already writing", __FUNCTION__);
return 0;
+ }
+ port->write_urb_busy = 1;
+ spin_unlock(&port->lock);
count = min(count, port->bulk_out_size);
memcpy(port->bulk_out_buffer, buf, count);
dbg("%s count now:%d", __FUNCTION__, count);
-
+
usb_fill_bulk_urb(port->write_urb, dev,
usb_sndbulkpipe(dev, port->bulk_out_endpointAddress),
port->write_urb->transfer_buffer,
@@ -418,6 +423,7 @@
ret = usb_submit_urb(port->write_urb, GFP_ATOMIC);
if (ret != 0) {
+ port->write_urb_busy = 0;
dbg("%s - usb_submit_urb(write bulk) failed with error = %d", __FUNCTION__, ret);
return ret;
}
