usb: Increase number of transfers from 2 to 4

Experimentally this has shown a much lower probability of
USB related overruns/underruns, at least on my system.

Change-Id: I5c73b29462a4870d3c86fd7f46e1574daae6f93f

1 files changed, 2 insertions, 2 deletions

diff --git a/src/usb.c b/src/usb.c
index 7f7f5c6..be4de44 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -365,8 +365,8 @@ _e1_usb_open_device(struct e1_daemon *e1d, struct libusb_device *dev)
 
 		line = e1_line_new(intf, line_data);
 
-		line_data->flow_in  = e1uf_create(line, e1_usb_xfer_in,  line_data->ep_in,  2, line_data->pkt_size, 4);
-		line_data->flow_out = e1uf_create(line, e1_usb_xfer_out, line_data->ep_out, 2, line_data->pkt_size, 4);
+		line_data->flow_in  = e1uf_create(line, e1_usb_xfer_in,  line_data->ep_in,  4, line_data->pkt_size, 4);
+		line_data->flow_out = e1uf_create(line, e1_usb_xfer_out, line_data->ep_out, 4, line_data->pkt_size, 4);
 		line_data->flow_fb  = e1uf_create(line, e1_usb_xfer_fb,  line_data->ep_fb,  2, 8, 1);
 
 		e1uf_start(line_data->flow_in);