Re: [PATCH 0/9] drm/i915/casf: Integrate the sharpness filter properly into the scaler code

["Sharma, Swati2" <swati2.sharma@intel.com>]

Hi Ville


On 01-04-2026 11:32 am, Sharma, Swati2 wrote:
> Hi Ville,
>
> On 31-03-2026 06:04 pm, Ville Syrjälä wrote:
>> On Tue, Mar 31, 2026 at 05:10:42PM +0530, Sharma, Swati2 wrote:
>>> Hi Ville,
>>>
>>> On 27-03-2026 04:01 am, Ville Syrjala wrote:
>>>> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
>>>>
>>>> The sharpness filter isn't anything special. It's just another
>>>> mode of the pipe scaler, so treat is as such.
>>>>
>>>> This gets rid of tons of special casing all over the place,
>>>> and will allow me to finally land the pending pipe prefill
>>>> series: https://patchwork.freedesktop.org/series/156137/
>>>>
>>>> Note that this will fail some kms_sharpness_filter tests,
>>>> because those tests are basically incorrect. But I couldn't
>>>> decide yet how much of that entire test should be nuked. It
>>>> seems to be doing a *lot* of things, most of which have
>>>> nothing to do with the sharpness filter...
>>> With your series I could see only 1 negative test failing -
>>> invalid-filter-with-scaling-mode-center
>>>
>>> https://intel-gfx-ci.01.org/tree/intel-xe/xe-pw-163952v1/shards-all.html?testfilter=sharpness 
>>>
>>>
>>> Is it sharpness and scaling-mode-center can work together? Since
>>> scaler-mode-center doesn't require
>>>
>>> scaler.
>>>
>>> You rightly said, all tests are not related to sharpness but covering
>>> valid scenarios for scaler + sharpness.
>>>
>>> Apart from invalid-filter-with-scaling-mode-center, which other 
>>> tests do
>>> you think are incorrect? We tried covering all valid scenarios as 
>>> per HAS.
>> I would probably nuke all these:
>>
>> Nothing to do with the sharpness filter since
>> it's on the pipe scaler, not plane scaler:
>> - filter-modifiers
>> - filter-rotations
>> - filter-formats
> Ack.
IGT patch floated https://patchwork.freedesktop.org/series/165542/

to remove above tests .

Can you please elaborate about sharpness filter vs. scaling filter test 
to be added?

Is it like applying
DRM_SCALING_FILTER_DEFAULT
DRM_SCALING_FILTER_NEAREST_NEIGHBOR
And SHARPNESS_FILTER
and doing some comparison?

>>
>> Doesn't seem to test anything at all:
>> - filter-tap
>
> Intention of this test is to validate different taps. As per spec,
>
> different TAPS will be selected based on different resolution selected.
>
>
> TAP 3: mode->hdisplay <= 1920 && mode->vdisplay <= 1080
> TAP 5: (mode->hdisplay > 1920 && mode->hdisplay < 3840) && 
> (mode->vdisplay > 1080 && mode->vdisplay < 2160)
> TAP 7: mode->hdisplay >= 3840 && mode->vdisplay >= 2160
>
>>
>> Maybe a decent idea, but really wasteful to have these kinds
>> of things for every little feature, as opposed to just
>> some generic "did we restore everything after dpms/suspend
>> correctly" test:
>> - filter-suspend
>> - filter-dpms
>
> True, but we did caught an issue during local testing with this test 
> where we were not able
>
> to retain sharpness after S/R.
>
>>
>> And I guess we're missing a test for sharpness filter vs.
>> scaling filter.
> Can you please little bit elaborate more?
>>
>> And the CRC stuff is really limited, so we have no idea if
>> the thing even works from these tests. But I guess we don't
>> really know the secret sauce algorithm, so generating a
>> reference image is hard :/
>
> Yes, right. For this we created chamelium specific test
>
> tests/chamelium/kms_chamelium_sharpness_filter.c
>
> where we are comparing frame dumps with and w/o sharpness enabled
>
> and you can clearly see difference when sharpness is applied. Though 
> we can't check
>
> degree of sharpness but can check if there was some change wrt reference.
>
> Test summary:
>
>     This test validates the content adaptive sharpness filter 
> functionality
>     by toggling the sharpness property on the CRTC and capturing frames
>     using Chamelium. It ensures that the filter visually alters the 
> output as
>     expected.
>
>         step 1. Display a test image with no sharpness filter.
>         step 2. Capture output (Frame 0).
>         step 3. Enable sharpness filter at mid strength.
>         step 4. Capture output (Frame 1).
>         step 5. Disable the filter again.
>         step 6. Capture output (Frame 2).
>         step 7. Re-enable filter with same strength.
>         step 8. Capture output (Frame 3).
>         step 9. Compare frame pairs:
>                     - Frame 0 vs Frame 1 → should differ
>                     - Frame 1 vs Frame 2 → should differ
>                     - Frame 0 vs Frame 2 → should match
>                     - Frame 1 vs Frame 3 → should match
>
>> If/when we get writeback we should be able vary the sharpness
>> strength and do a diff on the resulting images, and based on
>> that confirm that it actually did something that looks
>> reasonable.
>
> Sure, we do have plans to verify sharpness and colorops once WB is 
> enabled.
>
> So, for time being we are relying on chamelium with frame dumps.
>
>>
>>>> Cc: Nemesa Garg <nemesa.garg@intel.com>
>>>>
>>>> Ville Syrjälä (9):
>>>>     drm/i915/casf: s/casf_enable/enable/
>>>>     drm/i915/casf: Make a proper hw state copy of the 
>>>> sharpness_strength
>>>>     drm/i915/casf: Move the casf state to better place
>>>>     drm/i915/casf: Extract scaler_has_casf()
>>>>     drm/i915/casf: Handle CASF in skl_scaler_get_filter_select()
>>>>     drm/i915/casf: Constify crtc_state
>>>>     drn/i915/casf: Remove redundant argument from
>>>>       intel_casf_filter_lut_load()
>>>>     drm/i915/pfit: Call intel_pfit_compute_config() unconditionally on
>>>>       (e)DP/HDMI
>>>>     drm/i915/casf: Integrate the sharpness filter properly into the 
>>>> scaler
>>>>       code
>>>>
>>>>    drivers/gpu/drm/i915/display/intel_casf.c     | 102 
>>>> +++++-----------
>>>>    drivers/gpu/drm/i915/display/intel_casf.h     |   6 +-
>>>>    .../drm/i915/display/intel_crtc_state_dump.c  |  11 +-
>>>>    drivers/gpu/drm/i915/display/intel_display.c  |  46 ++------
>>>>    .../drm/i915/display/intel_display_debugfs.c  |   5 +-
>>>>    .../drm/i915/display/intel_display_types.h    |   5 +-
>>>>    drivers/gpu/drm/i915/display/intel_dp.c       |   9 +-
>>>>    drivers/gpu/drm/i915/display/intel_hdmi.c     |   8 +-
>>>>    .../drm/i915/display/intel_modeset_setup.c    |   1 +
>>>>    drivers/gpu/drm/i915/display/intel_pfit.c     |  13 ++-
>>>>    drivers/gpu/drm/i915/display/skl_scaler.c     | 110 
>>>> +++++++-----------
>>>>    drivers/gpu/drm/i915/display/skl_scaler.h     |   2 -
>>>>    12 files changed, 112 insertions(+), 206 deletions(-)
>>>>