openocd: fix SPDX tag format for files .c

[openocd.git] / src / jtag / drivers / kitprog.c

diff --git a/src/jtag/drivers/kitprog.c b/src/jtag/drivers/kitprog.c
index 0956d3aa6d82a7c2142516c5b69ac5af71b12357..0af1ff7a0e04b46e4662c8566179f9a7f9adc3b9 100644 (file)
--- a/src/jtag/drivers/kitprog.c
+++ b/src/jtag/drivers/kitprog.c
@@ -1,4 +1,4 @@
-/* SPDX-License-Identifier: GPL-2.0-or-later */
+// SPDX-License-Identifier: GPL-2.0-or-later
 
 /***************************************************************************
  *   Copyright (C) 2007 by Juergen Stuber <juergen@jstuber.net>            *
@@ -79,8 +79,24 @@
 #define HID_COMMAND_CONFIGURE  0x8f
 #define HID_COMMAND_BOOTLOADER 0xa0
 
-/* 512 bytes seems to work reliably */
-#define SWD_MAX_BUFFER_LENGTH 512
+/* 512 bytes seemed to work reliably.
+ * It works with both full queue of mostly reads or mostly writes.
+ *
+ * Unfortunately the commit 88f429ead019fd6df96ec15f0d897385f3cef0d0
+ * 5321: target/cortex_m: faster reading of all CPU registers
+ * revealed a serious Kitprog firmware problem:
+ * If the queue contains more than 63 transactions in the repeated pattern
+ * one write, two reads, the firmware fails badly.
+ * Sending 64 transactions makes the adapter to loose the connection with the
+ * device. Sending 65 or more transactions causes the adapter to stop
+ * receiving USB HID commands, next kitprog_hid_command() stops in hid_write().
+ *
+ * The problem was detected with KitProg v2.12 and v2.16.
+ * We can guess the problem is something like a buffer or stack overflow.
+ *
+ * Use shorter buffer as a workaround. 300 bytes (= 60 transactions) works.
+ */
+#define SWD_MAX_BUFFER_LENGTH 300
 
 struct kitprog {
        hid_device *hid_handle;
@@ -321,9 +337,13 @@ static int kitprog_hid_command(uint8_t *command, size_t command_length,
                return ERROR_FAIL;
        }
 
-       ret = hid_read(kitprog_handle->hid_handle, data, data_length);
-       if (ret < 0) {
-               LOG_DEBUG("HID read returned %i", ret);
+       ret = hid_read_timeout(kitprog_handle->hid_handle,
+                                                       data, data_length, LIBUSB_TIMEOUT_MS);
+       if (ret == 0) {
+               LOG_ERROR("HID read timed out");
+               return ERROR_TIMEOUT_REACHED;
+       } else if (ret < 0) {
+               LOG_ERROR("HID read error %ls", hid_error(kitprog_handle->hid_handle));
                return ERROR_FAIL;
        }