Cannot detect a NEO-supported device if there is another non-NEO-supported Intel device on the system

[agrn]

Hi,

I have a pretty peculiar system, with an i5-4690k and its associated iGPU (HD Graphics 4600), and an Arc A770. The iGPU is not supported by the NEO driver (instead, one should use the legacy intel-ocl or beignet drivers).

With the iGPU enabled, clinfo and other programs were not able to detect the Arc device, and clGetPlatformIDs() returned -1001 (CL_PLATFORM_NOT_FOUND_KHR).

straceing clinfo revealed that the correct ICD was loaded, and tried to access to two peripherals in /dev/dri, performed 2 various ioctl()s, and returned.

Disabling the iGPU in the system firmware (BIOS/UEFI) solved the issue.

This workaround satisfies me, but I can try to fix it if you accept contributions. I wanted to post this mostly because I did not find any info on this specific issue.

I will post the strace output as soon as possible.

[agrn]

Also, perhaps issue #663 is related?

[JablonskiMateusz]

hi @agrn
could you please share strace log ?

[agrn]

Sorry for the late answer.

Here is the log of strace with the iGPU enabled: clinfo-a770-hd4600.txt

(Sorry for the openat() noise, that's a side-effect of NixOS…)

libigdrcl.so is opened on line 70, and I believe the actual operation of the ICD begins around line 170. Both peripherals are opened on line 237 and 239. There is more ioctl()s than I remembered, though. At the end, you can see that there is no listing of OpenCL capabilities (ie. no platform were reported).

For contrast, here is the log of strace with the iGPU disabled: clinfo-a770-only.txt

You can see libigdrcl.so opened on line 70. A single device is opened this time, still on line 237.

Between these two runs, I only changed the iGPU setting in the system firmware.

[JablonskiMateusz]

@agrn could you verify if the issue is visible on most recent release?

It should be fixed in f63dd1f

[agrn]

Hi, I'm afraid I no longer have this system, and hence cannot test this change for now.