X-Git-Url: https://review.openocd.org/gitweb?a=blobdiff_plain;f=src%2Fjtag%2Fdrivers%2Fmpsse.c;h=41429693c15fe8a347de26cbf3e2d3a9b526e4b8;hb=30fde70c0321fd70d9330d5c6b56ed4e86653dd9;hp=92f9331a543c39385eaa538eaa64889bab62e879;hpb=452248af1d06cb1140b85f53ef4fdee1c746d807;p=openocd.git

diff --git a/src/jtag/drivers/mpsse.c b/src/jtag/drivers/mpsse.c
index 92f9331a54..41429693c1 100644
--- a/src/jtag/drivers/mpsse.c
+++ b/src/jtag/drivers/mpsse.c
@@ -55,7 +55,6 @@
 #define FTDI_DEVICE_OUT_REQTYPE (LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE)
 #define FTDI_DEVICE_IN_REQTYPE (0x80 | LIBUSB_REQUEST_TYPE_VENDOR | LIBUSB_RECIPIENT_DEVICE)
 
-#define BITMODE_RESET 0x00
 #define BITMODE_MPSSE 0x02
 
 #define SIO_RESET_REQUEST             0x00
@@ -313,19 +312,6 @@ struct mpsse_ctx *mpsse_open(const uint16_t *vid, const uint16_t *pid, const cha
 		goto error;
 	}
 
-	err = libusb_control_transfer(ctx->usb_dev,
-			FTDI_DEVICE_OUT_REQTYPE,
-			SIO_SET_BITMODE_REQUEST,
-			0x0b | (BITMODE_RESET << 8),
-			ctx->index,
-			NULL,
-			0,
-			ctx->usb_write_timeout);
-	if (err < 0) {
-		LOG_ERROR("unable to reset bitmode: %d", err);
-		goto error;
-	}
-
 	err = libusb_control_transfer(ctx->usb_dev,
 			FTDI_DEVICE_OUT_REQTYPE,
 			SIO_SET_BITMODE_REQUEST,
@@ -793,11 +779,8 @@ int mpsse_flush(struct mpsse_ctx *ctx)
 	if (ctx->read_count) {
 		buffer_write_byte(ctx, 0x87); /* SEND_IMMEDIATE */
 		read_result.done = false;
-		read_transfer = libusb_alloc_transfer(0);
-		libusb_fill_bulk_transfer(read_transfer, ctx->usb_dev, ctx->in_ep, ctx->read_chunk,
-			ctx->read_chunk_size, read_cb, &read_result,
-			ctx->usb_read_timeout);
-		retval = libusb_submit_transfer(read_transfer);
+		/* delay read transaction to ensure the FTDI chip can support us with data
+		   immediately after processing the MPSSE commands in the write transaction */
 	}
 
 	struct transfer_result write_result = { .ctx = ctx, .done = false };
@@ -806,6 +789,14 @@ int mpsse_flush(struct mpsse_ctx *ctx)
 		ctx->write_count, write_cb, &write_result, ctx->usb_write_timeout);
 	retval = libusb_submit_transfer(write_transfer);
 
+	if (ctx->read_count) {
+		read_transfer = libusb_alloc_transfer(0);
+		libusb_fill_bulk_transfer(read_transfer, ctx->usb_dev, ctx->in_ep, ctx->read_chunk,
+			ctx->read_chunk_size, read_cb, &read_result,
+			ctx->usb_read_timeout);
+		retval = libusb_submit_transfer(read_transfer);
+	}
+
 	/* Polling loop, more or less taken from libftdi */
 	while (!write_result.done || !read_result.done) {
 		retval = libusb_handle_events(ctx->usb_ctx);