usb_eacces.diff

diff --git a/usb.c b/usb.c
index 0f1875b..3cdb184 100644
--- a/usb.c
+++ b/usb.c
@@ -1120,6 +1120,7 @@ int usb_context_scan(struct iio_scan_backend_context *ctx,
 {
 	struct iio_context_info **info;
 	libusb_device **device_list;
+	bool had_eaccess = false, found_one = false;
 	unsigned int i;
 	int ret;
 
@@ -1133,10 +1134,14 @@ int usb_context_scan(struct iio_scan_backend_context *ctx,
 		unsigned int interface = 0;
 
 		ret = libusb_open(dev, &hdl);
+		if (ret == LIBUSB_ERROR_ACCESS)
+			had_eaccess = true;
 		if (ret)
 			continue;
 
 		if (!iio_usb_match_device(dev, hdl, &interface)) {
+			found_one = true;
+
 			info = iio_scan_result_add(scan_result, 1);
 			if (!info)
 				ret = -ENOMEM;
@@ -1150,7 +1155,10 @@ int usb_context_scan(struct iio_scan_backend_context *ctx,
 			goto cleanup_free_device_list;
 	}
 
-	ret = 0;
+	if (!found_one && had_eaccess)
+		ret = -EACCES;
+	else
+		ret = 0;
 
 cleanup_free_device_list:
 	libusb_free_device_list(device_list, true);