Exposure Fusion and Intel Neo drivers

[Entropy512 (Andy Dodd)]

@paperdigits

@Entropy512

Again - all Intel graphics hardware variants and all driver versions blacklisted, because one person had an issue on one of Intel’s lowest-end CPU/GPU combinations

Not sure where you’re getting this one person idea, but it is explained here: darktable and OpenCL (updated) | darktable

Just above the Summary section:

There also exist a few on-CPU implementations of OpenCL. These come as drivers provided by INTEL or AMD. We observed that they do not give us any speed gain versus our hand-optimized CPU code. Therefore we simply discard these devices.

We’re talking about Beignet/Neo, not CPU implementations.

Not once in that link are Beignet/Neo discussed.

Now, by doing some digging, one eventually finds the issue that drove that commit:
https://redmine.darktable.org/issues/12541

So, there are two procedural problems identified here:

1. As I already said, the commit in question has no description whatsoever, and does not reference the issue that drove it in any way, shape or form. No commit message, no comment in the code. One should not have to spend 20 minutes of Google searching to find something that should have been in the commit message or comments.
2. The developers immediately blamed the driver and blacklisted it across the board for all GPU variants and all possible driver versions, based on a single report - a report of a problem that turned out to be within darktable itself. (Failure to perform required cache invalidation of compiled kernels). The improper caching was solved by pull 2033 - yet the driver is still blacklisted.