[igt-dev] [PATCH i-g-t v2 1/2] kms_hdr: Skip HDR tests on pre-Kaby Lake Intel devices

[Petri Latvala]

On Mon, Mar 08, 2021 at 10:06:59AM -0500, Jeremy Cline wrote:
> On Mon, Mar 08, 2021 at 02:53:39PM +0200, Petri Latvala wrote:
> > On Mon, Mar 08, 2021 at 06:11:09PM +0530, Sharma, Swati2 wrote:
> > > 
> > > 
> > > On 08-Mar-21 2:17 PM, Petri Latvala wrote:
> > > > On Fri, Mar 05, 2021 at 11:42:52AM -0500, Jeremy Cline wrote:
> > > > > According to the Intel documentation[0] I could find, HDR support is
> > > > > only in Kaby Lake+. Skip tests in kms_hdr if the hardware doesn't
> > > > > support HDR.
> > > > > 
> > > > > [0] https://www.intel.com/content/dam/support/us/en/documents/graphics/HDR_Intel_Graphics_TechWhitePaper.pdf
> > > > > 
> > > > > Signed-off-by: Jeremy Cline <jcline at redhat.com>
> > > > 
> > > > 
> > > > While that might be true, strictly speaking IGT tests are not testing
> > > > the HW capabilities but the kernel interfaces. The difference is often
> > > > only interesting for nitpicking.
> > > > 
> > > > However, in this case a good argument can be made either way, with
> > > > what the correct behaviour with setting the "max bpc" property when
> > > > the HW doesn't support HDR _output_ should be. IGT tests should be
> > > > written the way one would expect "real" userspace to behave; does the
> > > > documented kernel interface require userspace to detect the device id
> > > > somehow? The connector property is there so one would assume setting
> > > > it should work and do something.
> > > > 
> > > > A good argument can also be made that even though we're testing "just
> > > > the interface", we (Intel) should have a separate test that requires
> > > > actual HW support...
> > > > 
> > > > Swati, Maarten, thoughts on this? Are we even testing the right things
> > > > for i915 at all? Are we able to express the HW requirement for HDR
> > > > with something other than comparing devid? Should we? (If we should
> > > > not, please suggest a better way to get around the issue being fixed
> > > > here)
> > > 
> > > There are 2 types of tests which are being validated in kms_hdr
> > > (i) bpc switch
> > > (ii) hdr metadata
> > > And both these tests will skip on platforms which doesn't support respective
> > > connector
> > > properties (MAX_BPC, HDR_OUTPUT_METADATA resp). These tests are independent
> > > of platforms on which they are being tested.
> > > This can be validated from the link below:
> > > https://intel-gfx-ci.01.org/tree/drm-tip/shards-all.html?testfilter=kms_hdr
> > > where you can see platforms which doesn't support either max_bpc or
> > > hdr_metadata
> > > connector properties; tests are being skipped.
> > > 
> > > And I don't think anything is being fixed here
> > 
> > What I meant is the fix in patch 2, removing the removal of the
> > primary plane, which was done because of a HSW limitation. Patch 1
> > (this thread) is then making sure HSW is unaffected by a spurious
> > failure. Sorry for not being clear when pulling more CCs.
> > 
> 
> There are definitely finer-grain ways to do this, but this "works" so I
> figured it'd be good to start here and have a discussion about it.
> 
> One option would be to just wrap the plane-removal call in a device
> check. Another would be to try and find a plane size that meets whatever
> the scaling requirements are for hsw (assuming there's overlap between
> the conflicting requirements of hardware).
> 
> I don't have a strong opinion about where the checks happen, it seems
> like a trade-off between in-test complexity and the breadth of the test
> matrix, and I can't say how useful it is to make sure the MAX_BPC
> interface works on a specific generation of hardware. I'm happy to do
> either of those options (or another option I've not considered),
> whatever you folks think is the best trade-off.


Checked how HSW actually behaves with this and

https://intel-gfx-ci.01.org/tree/drm-tip/TrybotIGT_300/shard-hsw4/igt@kms_hdr@bpc-switch.html

Swati, what's your opinion? if (amdgpudevice) around the plane removal
or what's best here?


-- 
Petri Latvala