From: Michael Gernoth <michael@gernoth.net>
Date: Sun, 7 Jul 2013 20:25:11 +0000 (+0200)
Subject: some changes in transfer-time-measurement
X-Git-Tag: v0.100~75
X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/hmcfgusb/commitdiff_plain/d200d8ca4e666defd3609ab2a8e058a20c419607

some changes in transfer-time-measurement
---

diff --git a/hmcfgusb.c b/hmcfgusb.c
index ce8c595..5939dd6 100644
--- a/hmcfgusb.c
+++ b/hmcfgusb.c
@@ -163,9 +163,10 @@ int hmcfgusb_send(struct hmcfgusb_dev *usbdev, unsigned char* send_data, int len
 
 	if (debug) {
 		hexdump(send_data, len, "USB < ");
-		gettimeofday(&tv_start, NULL);
 	}
 
+	gettimeofday(&tv_start, NULL);
+
 	err = libusb_interrupt_transfer(usbdev->usb_devh, EP_OUT, send_data, len, &cnt, USB_TIMEOUT);
 	if (err) {
 		fprintf(stderr, "Can't send data: %s\n", usb_strerror(err));
@@ -178,10 +179,14 @@ int hmcfgusb_send(struct hmcfgusb_dev *usbdev, unsigned char* send_data, int len
 		}
 	}
 
-	if (debug) {
-		gettimeofday(&tv_end, NULL);
-		msec = ((tv_end.tv_sec-tv_start.tv_sec)*1000)+((tv_end.tv_usec-tv_start.tv_usec)/1000);
-		fprintf(stderr, "send took %dms!\n", msec);
+	gettimeofday(&tv_end, NULL);
+	msec = ((tv_end.tv_sec-tv_start.tv_sec)*1000)+((tv_end.tv_usec-tv_start.tv_usec)/1000);
+
+	if (msec > 100) {
+		if (debug)
+			fprintf(stderr, "usb-transfer took more than 100ms (%dms), this can lead to timing problems!\n", msec);
+	} else if (debug) {
+		fprintf(stderr, "usb-transfer took %dms!\n", msec);
 	}
 
 	return 1;