jtag/mpsse: mpsse_flush should not treat LIBUSB_ERROR_INTERRUPTED as an error

LIBUSB_ERROR_INTERRUPTED can happen when (among other things) OpenOCD
process receives a signal like SIGHUP or SIGINT during a call to libusb.
Such situations are expected and should not be treated as an error - the
affected request should just be restarted.

Without this patch applied if a signal arrives during FTDI initialization
procedure we can easily end up (if JTAG speed is low) in situations like
https://review.openocd.org/c/openocd/+/4767. This happens because
fpsse_flush fails due to LIBUSB_ERROR_INTERRUPTED .

It should be noted that the current usage of mpsse_flush should be
revised since it seems that we don't always process error codes returned
by the function.

Change-Id: Ifa063ce828068f8d0371e1c2a864bb6174649848
Signed-off-by: Parshintsev Anatoly <anatoly.parshintsev@syntacore.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/7769
Reviewed-by: Tim Newsome <tim@sifive.com>
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>
Tested-by: jenkins

diff --git a/src/jtag/drivers/mpsse.c b/src/jtag/drivers/mpsse.c
index fad91dde2f80019a7be4227416f6d7098342e9ea..41a8b6e33fbcb0f6539ffc5712d3d385d1858c4b 100644 (file)
--- a/src/jtag/drivers/mpsse.c
+++ b/src/jtag/drivers/mpsse.c
@@ -880,20 +880,6 @@ int mpsse_flush(struct mpsse_ctx *ctx)
 
                retval = libusb_handle_events_timeout_completed(ctx->usb_ctx, &timeout_usb, NULL);
                keep_alive();
-               if (retval == LIBUSB_ERROR_NO_DEVICE || retval == LIBUSB_ERROR_INTERRUPTED)
-                       break;
-
-               if (retval != LIBUSB_SUCCESS) {
-                       libusb_cancel_transfer(write_transfer);
-                       if (read_transfer)
-                               libusb_cancel_transfer(read_transfer);
-                       while (!write_result.done || !read_result.done) {
-                               retval = libusb_handle_events_timeout_completed(ctx->usb_ctx,
-                                                               &timeout_usb, NULL);
-                               if (retval != LIBUSB_SUCCESS)
-                                       break;
-                       }
-               }
 
                int64_t now = timeval_ms();
                if (now - start > warn_after) {
@@ -901,6 +887,15 @@ int mpsse_flush(struct mpsse_ctx *ctx)
                                        "ms.", now - start);
                        warn_after *= 2;
                }
+
+               if (retval == LIBUSB_ERROR_INTERRUPTED)
+                       continue;
+
+               if (retval != LIBUSB_SUCCESS) {
+                       libusb_cancel_transfer(write_transfer);
+                       if (read_transfer)
+                               libusb_cancel_transfer(read_transfer);
+               }
        }
 
 error_check: