[Intel-gfx] [RFC i-g-t] tests: add runtime_pm

[Paulo Zanoni]

2013/11/4 Ville Syrjälä <ville.syrjala at linux.intel.com>:
> On Mon, Oct 28, 2013 at 10:20:56AM -0200, Paulo Zanoni wrote:
>> 2013/10/27 Daniel Vetter <daniel at ffwll.ch>:
>> > On Fri, Oct 25, 2013 at 11:44:05AM -0200, Paulo Zanoni wrote:
>> >> From: Paulo Zanoni <paulo.r.zanoni at intel.com>
>> >>
>> >> This test is based on pc8.c. It copies most of the tests from pc8.c,
>> >> but it depends on runtime PM status changes (parsed from sysfs)
>> >> instead of PC8 residency changes (parsed from the MSR registers).
>> >> There's also a test that checks for PC8 residency.
>> >>
>> >> For now, runtime PM and PC8 are different features, so having 2 test
>> >> suites makes sense. In the future we'll merge both, so we'll only get
>> >> PC8 when runtime PM is enabled, so we'll just kill pc8.c and keep
>> >> using runtime_pm.c.
>> >>
>> >> Changes compared to pc8.c:
>> >>   - We now look at the runtime PM status instead of PC8 residencies
>> >>   - Added more GEM tests (mmap, pread, execbuf, stress tests)
>> >>   - Added LPSP and non-LPSP tests
>> >>   - Added tests fro sysfs and debugfs files
>> >>   - Added a test specifically for PC8
>> >>
>> >> Signed-off-by: Paulo Zanoni <paulo.r.zanoni at intel.com>
>> >
>> > Since the actual tests we're running are so similar I prefer if we merge
>> > all the runtime pm tests in one file. It makes testcase maintaince (and
>> > bufixing, that happens) much easier. I guess a struct per runtime pm
>> > method (pc8, D3, ...) with a few vfuncs should get things going. The
>> > overall test would loop over all the pm methods and try to set things up.
>> > Then loop over all subtests and either skip them all (if that particular
>> > runtime pm method isn't supported) or just run them.
>> >
>> > We've had a few other case of massive copy&pasting in i-g-t and in the
>> > past few months I've merged most of them back again.
>>
>> At this moment I'm really leaning towards merging PC8 and D3 into a
>> single feature, so it won't be possible to test them in separate
>> anymore. With this, we'd just have runtime_pm.c and we'd completely
>> kill pc8.c.
>
> All this time I've been wondering whether PC8 offers anything
> substantial over D3.

It's more like "PC8 is a diet D3". I don't see why anyone would want
PC8 without D3.

> I think we discussed this in some meeting, and
> GTT maps were the only thing that came to my mind. But IIRC you
> said that you weren't actually sure whether GTT maps still work in
> PC8. Has that been verified or is it still an open question?

Daniel also asked for this test. This week I finally had some time to
go back to this. I just added a test for GTT mmaps and the test fails
while we're on D3 (didn't try PC8-without-D3 yet). Clever ideas on how
to fix the problem are always welcome :)

>
> --
> Ville Syrjälä
> Intel OTC



-- 
Paulo Zanoni