[igt-dev] [PATCH v8 1/1 i-g-t] tests: Add a new test for driver/device hot reload

[Janusz Krzysztofik]

Hi Daniel,

On Tuesday, May 7, 2019 3:32:10 PM CEST Daniel Vetter wrote:
> ...
> Another option would be to first have a more minimal hotunplug test
> without any busy batches pending, and make sure that works reliable
> (i.e. no buffer, no context, no nothing, no open fd, absolutely
> nothing really allocated from userspace). Then extend from there
> step-by-step, e.g. first just open a drm device fd, then allocate a
> buffer, then mmap, then maybe try to write to that buffer after
> unplug, try to do an ioctl after unplug (go through all of them).
> 
> Only once you've gone through all the more basic things go to the much
> more evil stuff like having a batch in-flight, or a kms request
> in-flight. That way it should be easier to make forward progress on
> these bugs without risking the world. Plus you can start merging the
> igt side already, to make sure no one regresses anymore.

It looks like I might have misunderstood your idea.  Did you mean I should 
start with a patch that adds only the minimal hotunplug test and nothing more? 
Then extend it with more advanced subtests one by one consecutively but only 
when driver issues revealed by those subtests already in place are resolved?

If that's the case, I should probably submit v10 limited to the minimal test 
since v9 I submitted last week was not going to be taken under consideration.

Thanks,
Janusz