I run some opencl applications on 2x AMD Radeon HD 7870 on a machine running Ubuntu 13.10.

I power the machine on and lightdm has the login prompt. Since I cannot physically be present to login to the machine everytime I power cycle it. I want to troubleshoot why Opencl does not detect the GPU following a power cycle on the machine.

Without logging in in lightdm , if I ssh into the machine and start the opencl jobs.
Opencl does not "see" the GPU.

Only If I login to the machine by being physically present and logging into lightdmdoes the remote shell "see" the GPU.

I dont know much about openCL to provide more information, but this seems to be something about how ubuntu initializes. What does logging in to the lightdm console ..do to the state of the graphics driver.

Is there some way to "load" the driver to have OpenCL see it.

Strangely lsmod shows "fglrx" loaded and in use when Opencl fails to "see" the GPU.

State without loggin into lightdm and as reported by a ssh session

   hari@hjubuntu:~$ ~/oepncl-program



    Available device list:

    Type: CPU, 'Intel(R) Core(TM)2 Quad  CPU   Q9450  @ 2.66GHz'





hari@hjubuntu:~$ lsmod

    Module                  Size  Used by

    pci_stub               12622  1 

    vboxpci                23194  0 

    vboxnetadp             25670  0 

    vboxnetflt             27613  0 

    vboxdrv               320455  3 vboxnetadp,vboxnetflt,vboxpci

    cuse                   13274  3 

    dm_crypt               22832  0 

    kvm_intel             138567  0 

    kvm                   431754  1 kvm_intel

    gpio_ich               13476  0 

    ppdev                  17671  0 

    snd_usb_audio         149162  2 

    bnep                   19704  2 

    snd_usbmidi_lib        25070  1 snd_usb_audio

    rfcomm                 69130  0 

    bluetooth             372041  10 bnep,rfcomm

    snd_hda_codec_hdmi     41154  2 

    microcode              23656  0 

    psmouse                97655  0 

    snd_hda_codec_realtek    56475  1 

    serio_raw              13413  0 

    snd_seq_midi           13324  0 

    snd_hda_intel          52267  7 

    snd_seq_midi_event     14899  1 snd_seq_midi

    snd_hda_codec         188738  3 snd_hda_codec_realtek,snd_hda_codec_hdmi,snd_hda_intel

    snd_rawmidi            30095  2 snd_usbmidi_lib,snd_seq_midi

    snd_hwdep              13602  2 snd_usb_audio,snd_hda_codec

    lpc_ich                21080  0 

    snd_pcm               102033  4 snd_usb_audio,snd_hda_codec_hdmi,snd_hda_codec,snd_hda_intel

    snd_seq                61560  2 snd_seq_midi_event,snd_seq_midi

    snd_page_alloc         18710  2 snd_pcm,snd_hda_intel

    snd_seq_device         14497  3 snd_seq,snd_rawmidi,snd_seq_midi

    snd_timer              29433  2 snd_pcm,snd_seq

    fglrx                8815330  48 

    snd                    69141  31 snd_hda_codec_realtek,snd_usb_audio,snd_hwdep,snd_timer,snd_hda_codec_hdmi,snd_pcm,snd_seq,snd_rawmidi,snd_usbmidi_lib,snd_hda_codec,snd_hda_intel,snd_seq_device,snd_seq_midi

    it87                   43113  0 

    hwmon_vid              12783  1 it87

    parport_pc             32701  1 

    coretemp               13435  0 

    x38_edac               12898  0 

    soundcore              12680  1 snd

    lp                     17759  0 

    parport                42299  3 lp,ppdev,parport_pc

    binfmt_misc            17468  1 

    mac_hid                13205  0 

    amd_iommu_v2           19054  1 fglrx

    edac_core              62342  1 x38_edac

    vesafb                 13828  1 

    pata_acpi              13038  0 

    hid_generic            12548  0 

    usbhid                 53014  0 

    hid                   101762  2 hid_generic,usbhid

    firewire_ohci          40327  0 

    firewire_core          64534  1 firewire_ohci

    crc_itu_t              12707  1 firewire_core

    r8169                  67581  0 

    mii                    13934  1 r8169

    pata_jmicron           12758  0 

    ahci                   25819  0 

    libahci                32009  1 ahci

    floppy                 69370  0 

After the user logs in and I run the same program.

State after loggin in to lightdm and starting the desktop environment

hari@hjubuntu:~$ ~/opencl-program

Available device list:

Type: CPU, 'Intel(R) Core(TM)2 Quad  CPU   Q9450  @ 2.66GHz'

Type: GPU, 'Pitcairn'

Type: ACCELERATOR, 'Pitcairn'

Now If I do a diff of the lsmod
What I get is

hari@hjubuntu:~$ diff before_login after_login | grep fglrx

<     fglrx                8815330  48 

<     amd_iommu_v2           19054  1 fglrx

> fglrx                8815330  44 

> amd_iommu_v2           19054  1 fglrx

SO logging in caused the fglrx driver to get used by "44". How do I mimic this so I got have to log in when someone remote-power cycles this machine?.

edit: I am trying to implement the script below and always get a

"hari@hjubuntu:~$ xauth extract "$DISPLAY"

xauth: (argv):1:  bad "extract" command line"

The $DISPLAY environment label is blank

hari@hjubuntu:~$ echo $DISPLAY

xauth list gives

hjubuntu/unix:1  MIT-MAGIC-COOKIE-1  8562e9f6ac976f310d1425aa11e74184

hjubuntu:0  MIT-MAGIC-COOKIE-1  80f5f4c28e7e2d0fc9444b1862f5cbcb

hjubuntu:0  MIT-MAGIC-COOKIE-1  80f5f4c28e7e2d0fc9444b1862f5cbcb

hjubuntu/unix:13  MIT-MAGIC-COOKIE-1  142c11b5689f4bd2776e860b9d8719dd

hjubuntu/unix:14  MIT-MAGIC-COOKIE-1  08353f652f21b479a6da3a60282bce31

hjubuntu/unix:15  MIT-MAGIC-COOKIE-1  655d074dfb395f536283e70a9494428c

hjubuntu/unix:12  MIT-MAGIC-COOKIE-1  91387509c2dff960e295fdd0eb0ada52

hjubuntu/unix:11  MIT-MAGIC-COOKIE-1  914c7988660149b90eed958066ed2e71

hjubuntu/unix:10  MIT-MAGIC-COOKIE-1  0ab65dbaf838a08bd8c9141fb5da7c35

Wondering how I should proceed.