[Beignet] Beignet not working on Dell Precision M3800

[Yichao Yu]

> [Rong]: Screen frozen may be GPU hang, can you provide your tests or kernel, then I will reproduce and fix it.

There seems to be multiple ones but at least here is one of them:

I was using the pyopencl[1] test cases[2] (cuz I am developing the
cffi version for pypy) and the two test cases that are failing in
`test_wrapper.py` are `test_image_3d`[4] and `test_copy_buffer`[5].
The 3d image test fail with invalid image format error (is 3d image
not supported) and the copy buffer test hang the GPU without doint
anything (the returned buffer is empty).

I have created a c version for you to reproduce here[6], in which you
can modify the `BUF_SIZE`. On my computer, it fails for all the
numbers I have tried from 1 to 50000 so it shouldn't be the problem of
too big data transfer (and .... in any cases copying 50000 numbers
shouldn't take seconds :P). I haven't played with the flag for
creating buffers but at least the current flags have 100%
reproducibility here ....

[1] https://github.com/pyopencl/pyopencl/
[2] https://github.com/pyopencl/pyopencl/tree/master/test
[3] https://github.com/pyopencl/pyopencl/blob/master/test/test_wrapper.py
[4] https://github.com/pyopencl/pyopencl/blob/master/test/test_wrapper.py#L396
[5] https://github.com/pyopencl/pyopencl/blob/master/test/test_wrapper.py#L471
[6] https://gist.github.com/yuyichao/242fd2a812088930af91

>
> [Rong]: Yes, must hack the kernel to walk around it now, and the drm driver team is handling it now, but maybe need some time.

Good to know at least someone are working on it.

>
>
> Looking forward to full support soon.
>
> Yichao Yu
>
>>
>> Thanks
>>
>