/dev/nv* permissions incorrect for other users after reset

Autonomous Machines Jetson & Embedded Systems Jetson TX1
#1

I believe this may be a bug in jetpack 2.2.1. Reproduce case:

  • login as ubuntu user
  • create a new user as follows: ``` sudo adduser anewuser sudo usermod -a -G sudo anewuser ```
  • ssh in as the new user. Try to run the deviceQuery executable from the CUDA Samples. Receive error ``` /home/ubuntu/NVIDIA_CUDA-7.0_Samples/bin/aarch64/linux/release/deviceQuery Starting...

    CUDA Device Query (Runtime API) version (CUDART static linking)

    cudaGetDeviceCount returned 30
    -> unknown error
    Result = FAIL

    
</li>
<li>Type

    sudo chmod 0666 /dev/nv*

     to fix the permissions on the /dev/nv files.
</li>
<li>Retry deviceQuery.  It should work now.</li>
<li>press the reset button on the device.</li>
<li>login as the new user</li>
<li>Try to run deviceQuery again and observe a failure.  Retype the chmod command to get it working again.</li>

</ul>



Hopefully this can get into the next release of JP.
#2

FYI, JetPack version does not necessarily say which version of L4T is installed on the Jetson…JetPack is a front end installer and only installs other software on the Jetson without JetPack itself being put on the Jetson. Knowing your L4T version is via “head -n 1 /etc/nv_tegra_release”.

In terms of CUDA and GPU access you need to also add your new user to group “video”. The same command you used for adding the user to sudo will work, just use “-G video” instead of “-G sudo” (in which case the chmod is no longer needed).

#3

Hi - thank you! this works great.

Cheers!