I'm using the latest fosphor from git (7b6b9961bc2d9b84daeb42a5c8f8aeba293d207c) and am seeing two weird (and I believe related) issues. Firstly, I see the following error:
[+] Selected device: TITAN X (Pascal)
[!] CL Error (-30, /home/user/gr-fosphor/lib/fosphor/cl.c:409): Unable to queue clear of spectrum buffer
This is CL_INVALID_VALUE returning from clEnqueueFillBuffer, so I added some debug fprints to cl.c to see what parameters were being passed into clEnqueueFillBuffer:
Edits:
fprintf(stderr, "size = %d\n", 2 * 2 * sizeof(cl_float) * FOSPHOR_FFT_LEN);
fprintf(stderr, "pattern_size = %d\n", sizeof(float));
fprintf(stderr, "pattern = %p\n", &noise_floor);
fprintf(stderr, "offset = %d\n", 0);
Output:
size = 16384
pattern_size = 4
pattern = 0x7fb66b7fdd2c
offset = 0
These parameters look like they shouldn't cause CL_INVALID_VALUE:
But there is this one condition that might be met, which is that somehow size (16384) is larger than the underlying buffer (cl->mem_spectrum). The underlying OpenGL buffer being too small brings me to my next (I believe related) issue. The spectrum plot in fosphor is weirdly pixelated, please see the attachment, which shows a screencap from "osmocom_fft -F -f 100e6 -g 20 -s 10e6".
Where is the cl->mem_spectrum buffer ultimately declared / initialized? My OpenCL / OpenGL sharing knowledge is nonexistent, any pointers for how I can help debug this issue?
Output of clinfo is attached as well, and I'm on Ubuntu 16.04 on x86_64.
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Raj Bhattacharjea, PhD
Georgia Tech Research Institute
Information and Communications Laboratory
404.407.6622