From 4c5ce0b16afe3b7ca88c39282147926bc15dff41 Mon Sep 17 00:00:00 2001
From: Uwe Bonnes <bon@elektron.ikp.physik.tu-darmstadt.de>
Date: Wed, 9 Dec 2020 17:33:47 +0100
Subject: [PATCH] Hosted: Handle devices w/o serial number, e.g. GigaDevices
 GD-Link ARM/CMSIS-DAP

---
 src/platforms/hosted/bmp_libusb.c | 20 +++++++++++++-------
 src/platforms/hosted/cmsis_dap.c  |  6 +++---
 2 files changed, 16 insertions(+), 10 deletions(-)

diff --git a/src/platforms/hosted/bmp_libusb.c b/src/platforms/hosted/bmp_libusb.c
index 30abda8d..e24bdda6 100644
--- a/src/platforms/hosted/bmp_libusb.c
+++ b/src/platforms/hosted/bmp_libusb.c
@@ -98,12 +98,19 @@ int find_debuggers(BMP_CL_OPTIONS_t *cl_opts,bmp_info_t *info)
 	char serial[64];
 	char manufacturer[128];
 	char product[128];
-	bmp_type_t type = BMP_TYPE_NONE;
+	bmp_type_t type;
 	bool access_problems = false;
 	char *active_cable = NULL;
 	bool ftdi_unknown = false;
   rescan:
+	type = BMP_TYPE_NONE;
 	found_debuggers = 0;
+	serial[0] = 0;
+	manufacturer[0] = 0;
+	product[0] = 0;
+	access_problems = false;
+	active_cable = NULL;
+	ftdi_unknown = false;
 	for (int i = 0;  devs[i]; i++) {
 		libusb_device *dev =  devs[i];
 		int res = libusb_get_device_descriptor(dev, &desc);
@@ -130,12 +137,8 @@ int find_debuggers(BMP_CL_OPTIONS_t *cl_opts,bmp_info_t *info)
 		res = libusb_get_string_descriptor_ascii(
 			handle, desc.iSerialNumber, (uint8_t*)serial,
 			sizeof(serial));
-		if (res <= 0) {
-			/* This can fail for many devices. Continue silent!*/
-			libusb_close(handle);
-			continue;
-		}
-		if (cl_opts->opt_serial && !strstr(serial, cl_opts->opt_serial)) {
+		if (cl_opts->opt_serial && ((res <= 0) ||
+			!strstr(serial, cl_opts->opt_serial))) {
 			libusb_close(handle);
 			continue;
 		}
@@ -154,6 +157,9 @@ int find_debuggers(BMP_CL_OPTIONS_t *cl_opts,bmp_info_t *info)
 				libusb_close(handle);
 				continue;
 			}
+		} else {
+			libusb_close(handle);
+			continue;
 		}
 		libusb_close(handle);
 		if (cl_opts->opt_ident_string) {
diff --git a/src/platforms/hosted/cmsis_dap.c b/src/platforms/hosted/cmsis_dap.c
index 8abd9d7e..c1e9668f 100644
--- a/src/platforms/hosted/cmsis_dap.c
+++ b/src/platforms/hosted/cmsis_dap.c
@@ -56,18 +56,18 @@ int dap_init(bmp_info_t *info)
 	if (hid_init())
 		return -1;
 	int size = strlen(info->serial);
-	wchar_t serial[size + 1], *wc = serial;
+	wchar_t serial[64] = {0}, *wc = serial;
 	for (int i = 0; i < size; i++)
 		*wc++ = info->serial[i];
 	*wc = 0;
-	/* Blacklist devices that do not wirk with 513 byte report length
+	/* Blacklist devices that do not work with 513 byte report length
 	 * FIXME: Find a solution to decipher from the device.
 	 */
 	if ((info->vid == 0x1fc9) && (info->pid == 0x0132)) {
 		DEBUG_WARN("Blacklist\n");
 		report_size = 64 + 1;
 	}
-	handle = hid_open(info->vid, info->pid, serial);
+	handle = hid_open(info->vid, info->pid,  (serial[0]) ? serial : NULL);
 	if (!handle)
 		return -1;
 	dap_disconnect();