only read pins when needed, now it's a bit faster than a parallel cable

jtagkey.c

@@ -209,6 +209,8 @@ int jtagkey_transfer(WD_TRANSFER *tr, int fd, unsigned int request, int ppbase,
 		DPRINTF("writing %d bytes\n", writepos-writebuf);
 		for (i=0; i<writepos-writebuf; i++) {
 			ftdi_write_data(&ftdic, writebuf+i, 1);
+
+			if (i > 0 && tr[i].cmdTrans == PP_WRITE && tr[i-1].cmdTrans == PP_READ)
 				ftdi_read_pins(&ftdic, readbuf+i);
 		}