3.3.5. LTP-DDT Validation

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LTP-DDT Overview

LTP-DDT is a test application used by Texas Instruments to validate Linux releases.

It is based on LTP.
LTP validates many kernel areas, such as memory management, scheduler and system calls. LTP-DDT extends LTP’s core Kernel tests with tests to validate Kernel drivers developed by Texas Instruments. LTP-DDT focuses on embedded device driver tests. It contains hundreds of tests that validate functionality and performance of device drivers. LTP-DDT also contains tests to validate System’s use cases and overall System’s stability.

LTP-DDT uses LTP’s test infrastructure, such as:

  • Test execution drivers (PAN)
  • Top-level test scripts (i.e. runltp)
  • Same Folder Hierarchy and test case definition format

LTP-DDT test cases are LTP test cases and vice-versa.

The main additions or ‘enhacements’ of LTP-DDT compared to LTP are:

  • PLATFORM files. LTP-DDT uses PLATFORM files to identify platform hardware and software features.
  • OVERRIDE mechanism. Default test case parameters are automatically overridden based on PLATFORM features.
  • ATOMIC scripts. Code reuse is foster by writing scripts that implement small well-defined actions. Test scripts rely on these atomic scripts to execute their actions.
  • AUTOMATIC FILTERING. Test cases are filtered based on the test requirements and the PLATFORM features.
  • TESTCASE ANNOTATIONS. Test scenario files are annotated with following annotations @name, @desc, @requires and @setup_requires. The @requires and @setup_requires are used to select test cases at run time based on the PLATFORM features.
  • All LTP-DDT test cases and test code reside in <testcases-root>/ddt/ and <testcode-root>/ddt/ folders respectively.

LTP-DDT Highlights

  • Easy to use (automatically filter test cases not applicable for platform)
  • Easy to support new platforms (just define the platform file)
  • Test cases can be easily wrap or imported to Test Management Systems (Use of testcase annotations facilitates this)
  • High Code Reuse (atomic scripts and test scripts are reused and parameters are adjusted on the fly)

Test Suites

LTP-DDT contains tests cases that uses other open source tools such as iperf, evtest, rt-tests (cyclictest), lmbench and others.
Test suites currently available include among others:
  • alsa
  • cpu hotplug
  • crypto
  • timers
  • emmc
  • mmc/sd
  • ethernet
  • fbdev
  • gpio
  • gstreamer (multimedia)
  • hdmi
  • i2c
  • ipc
  • latency under different use cases (important for RT kernel)
  • lmbench
  • memory tests
  • mm (ltp’s memory management)
  • msata
  • nand
  • nor
  • pci
  • pipes (ltp)
  • power management
  • programmable real-time unit (PRU)
  • pwm
  • qspi
  • realtime (ltp)
  • rng
  • rtc
  • sata
  • scheduler (ltp)
  • sgx (graphics)
  • smp
  • spi
  • syscalls (ltp)
  • system (use-cases, e.g. multiple tests running in parallel)
  • thermal
  • timers (ltp)
  • touchscreen
  • uart
  • usb host (multiple tests with different classes)
  • usb device
  • v4l2
  • vlan
  • dwt
  • wlan

Device Under Tests Supported

LTP-DDT has been used on following devices:

LTP-DDT Devices
am170x-evm am389x-evm am57xx-beagle-x15 da850-omapl138-evm dra72x-hsevm k2e-evm omap3evm
am180x-evm am437x-idk am57xx-evm dm365-evm dra76x-evm k2e-hsevm omap5-evm
am181x-evm am437x-sk am57xx-hsevm dm368-evm dra7xx-evm k2g-evm omapl138-lcdk
am335x-evm am43xx-epos am654x-evm dm385-evm dra7xx-hsevm k2g-hsevm pandaboard-es
am335x-hsevm am43xx-gpevm am654x-hsevm dm6467-evm dragonboard410c k2g-ice sdp3430
am335x-ice am43xx-hsevm am654x-idk dm813x-evm hikey k2hk-evm tci6614-evm
am335x-sk am571x-idk beagleboard dra71x-evm j721e-evm k2hk-hsevm ti811x-evm
am3517-evm am572x-idk beaglebone dra71x-hsevm j721e-evm-ivi k2l-evm ti813x-evm
am37x-evm am574x-hsidk beaglebone-black dra71x-lcard j721e-idk-gw k2l-hsevm  
am387x-evm am574x-idk da830-omapl137-evm dra72x-evm      

Host Platform Requirements

Linux host is required :

  • for compiling LTP-DDT.
  • to host the NFS server to boot the EVM with NFS as root filesystem
  • to run host utilities - e.g.iperf

Host Software Requirements

  • GCC Tool chain for ARM
  • Serial console terminal application
  • TFTP and NFS servers. NFS server is required only in case of NFS boot.
  • iperf utility on the host.

Filesystem Requirements

LTP-DDT relies on other open source test tools. The following test tools must be available in the target filesystem to run ltp-ddt:

  • alsa utilities
  • evtest
  • hdparm
  • iperf
  • lmbench
  • rt-tests (cyclictest)

There is an Arago/OE recipe here that builds a filesystem image w/ the above tools plus:

  • bonnie++
  • iozone3
  • ltp-ddt


Clone the project

git clone http://arago-project.org/git/projects/test-automation/ltp-ddt.git
Installation instructions are in the README-DDT file. Check sections 6) and 7)
There is also an Arago/OE recipe to build ltp-ddt here

Running Tests

  • Run DDT tests the same way you run LTP tests. Use ltprun program and pass to

it the test scenario file in the runtest directory (option -f) to run and the platform (option -P) to use. For example:

./runltp -P am180x-evm -f ddt/lmbench
The platform name specified with -P option must exist in the platforms/ dir.
It is also possible to run tests without -P option, in such case the ltprun script won’t filter test cases and it is possible that tests cases not supported by the platform you are running on will be called.
  • In addition to selecting test scenarios using -f option, users can also
filter test cases using -s PATTERN option. These option select test cases based on the test case TAG specified in the test scenario file.
  • The runltp script have lot of options. Some useful ones for stress tests are:
-t DURATION: Define duration of the test in s,m,h,d.
-x INSTANCES: Run multiple test instances in parallel.
-c <options>: Run test under additional background CPU load
-D <options>: Run test under additional background load on Secondary storage
-m <options>: Run test under additional background load on Main memory
-i <options>: Run test under additional background load on IO Bus
-n          : Run test with network traffic in background.

Please refer to README-DDT file section 8) for more details.

  • Running NAND Sanity Tests

– Run all NAND sanity tests

Using below command to run NAND sanity tests.

./runltp -P <platform> -s "NAND_S_" -S skiplist

If there are more than one flash filesystem supported, say, jffs2 and ubifs and you don’t run jffs2 test cases. You need create a file called ‘skiplist’ (this filename could be anything) and put to-be-skipped test case tag in this file. Here is the content of skiplist to skip jffs2 test cases.

@ cat skiplist

– Run NAND performance test

./runltp -P <platform> -s "NAND_L_PERF" -S skiplist


LTP-DDT is an open source project.
Developers are encouraged to join the Opentest mailing list at http://arago-project.org/cgi-bin/mailman/listinfo/opentest
Of course patches and comments are welcome, please send them to opentest@arago-project.org mailing list.
Developers are encouraged to read sections 3) and 4) in the README-DDT file before submitting patches.