Re: [PATCH 0/4] add test to validate uhbr/non-uhbr over sst/mst

[Jani Nikula <jani.nikula@intel.com>]

On Tue, 28 Jan 2025, "Joshi, Kunal1" <kunal1.joshi@intel.com> wrote:
> Hello Jani,
>
> Thanks for taking a look,
>
> On 27-01-2025 18:01, Jani Nikula wrote:
>> On Wed, 15 Jan 2025, Kunal Joshi<kunal1.joshi@intel.com> wrote:
>>> Add new test validating UHBR and non-UHBR link rates for
>>> both SST and MST configurations. The series comprises three patches:
>>>
>>> 1. tests/intel/kms_joiner_helper:
>>>     - Introduces kms_joiner_helper.c/h for pipe assignments taking care of joiners
>>>     - Moves common joiner-related logic out of kms_joiner.c.
>>>
>>> 2. tests/intel/kms_mst_helper:
>>>     - Adds kms_mst_helper.c/h for MST-specific operations.
>>>     - Centralizes code for identifying and assigning MST outputs.
>>>
>>> 3. tests/kms_feature_discovery:
>>>     - Implements tests verifying UHBR and non-UHBR link rates with SST and MST.
>>>     - Uses the new helpers for pipe assignments and topology discovery.
>> AFAICT this adapts to what the driver reports. If the driver never
>> enables DP SST UHBR, it'll happily pass, and just skip the tests. Am I
>> right? Is that the kind of testing you want?
>>
>>
>> BR,
>> Jani.
> The purpose of the |kms_feature_discovery| test is to verify that all 
> necessary configurations are in place. If a DP 2.1 SST monitor is not 
> connected in the CI environment, the test will be skipped, indicating 
> that SST UHBR coverage is missing. Since DP 2.1 SST support is already 
> provided by existing tests, this test simply confirms whether the 
> appropriate monitor is available to enable that coverage.

I haven't been closely following IGT testing strategy lately, but you
asked me to have a look at this regardless, so I did. I'm not going to
comment on the details in this series or review it. The only question
is, if the driver decides to incorrectly use non-UHBR SST on a UHBR SST
capable sink, who is going to notice? Or if it works now, and breaks
later, is some test going to fail instead of skip?


BR,
Jani.


>
> Thanks and Regards Kunal Joshi
>>
>>
>>> Kunal Joshi (4):
>>>    tests/intel/kms_joiner_helper: helper for joiner-related functions
>>>    tests/intel/kms_mst_helper: Add helper for MST-related functions
>>>    tests/kms_feature_discovery: Add tests for UHBR/non-UHBR over SST/MST
>>>    HAX: DO NOT MERGE
>>>
>>>   tests/intel-ci/fast-feedback.testlist    |  14 ++
>>>   tests/intel-ci/xe-fast-feedback.testlist |  14 ++
>>>   tests/intel/kms_dp_linktrain_fallback.c  |  28 +---
>>>   tests/intel/kms_joiner.c                 |  15 +-
>>>   tests/intel/kms_joiner_helper.c          | 179 +++++++++++++++++++++++
>>>   tests/intel/kms_joiner_helper.h          |  15 ++
>>>   tests/intel/kms_mst_helper.c             |  48 ++++++
>>>   tests/intel/kms_mst_helper.h             |  10 ++
>>>   tests/kms_feature_discovery.c            | 177 ++++++++++++++++++++++
>>>   tests/meson.build                        |   6 +
>>>   10 files changed, 469 insertions(+), 37 deletions(-)
>>>   create mode 100644 tests/intel/kms_joiner_helper.c
>>>   create mode 100644 tests/intel/kms_joiner_helper.h
>>>   create mode 100644 tests/intel/kms_mst_helper.c
>>>   create mode 100644 tests/intel/kms_mst_helper.h

-- 
Jani Nikula, Intel