X-Git-Url: https://git.zerfleddert.de/cgi-bin/gitweb.cgi/hmcfgusb/blobdiff_plain/f8718b41a21fa51202f465dbe4238892e9f2f647..d26506bfa2b8d190cae9af9ca251564d3db0156e:/hmcfgusb.c

diff --git a/hmcfgusb.c b/hmcfgusb.c
index 1ba9b24..65b4763 100644
--- a/hmcfgusb.c
+++ b/hmcfgusb.c
@@ -140,6 +140,20 @@ static libusb_device_handle *hmcfgusb_find() {
 	return NULL;
 }
 
+int hmcfgusb_send_null_frame(struct hmcfgusb_dev *usbdev)
+{
+	int err;
+	int cnt;
+
+	err = libusb_interrupt_transfer(usbdev->usb_devh, EP_OUT, NULL, 0, &cnt, USB_TIMEOUT);
+	if (err) {
+		fprintf(stderr, "Can't send data: %s\n", usb_strerror(err));
+		return 0;
+	}
+
+	return 1;
+}
+
 int hmcfgusb_send(struct hmcfgusb_dev *usbdev, unsigned char* send_data, int len, int done)
 {
 	int err;
@@ -149,9 +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));
@@ -159,17 +174,18 @@ int hmcfgusb_send(struct hmcfgusb_dev *usbdev, unsigned char* send_data, int len
 	}
 
 	if (done) {
-		err = libusb_interrupt_transfer(usbdev->usb_devh, EP_OUT, send_data, 0, &cnt, USB_TIMEOUT);
-		if (err) {
-			fprintf(stderr, "Can't send data: %s\n", usb_strerror(err));
+		if (!hmcfgusb_send_null_frame(usbdev)) {
 			return 0;
 		}
 	}
 
-	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) {
+		fprintf(stderr, "usb-transfer took more than 100ms (%dms), this may lead to timing problems!\n", msec);
+	} else if (debug) {
+		fprintf(stderr, "usb-transfer took %dms!\n", msec);
 	}
 
 	return 1;
@@ -391,6 +407,9 @@ int hmcfgusb_poll(struct hmcfgusb_dev *dev, int timeout)
 	} else {
 		if ((tv.tv_sec == 0) && (tv.tv_usec == 0)) {
 			usb_event = 1;
+		} else if (tv.tv_sec > timeout) {
+			tv.tv_sec = timeout;
+			tv.tv_usec = 0;
 		}
 	}