Re: [PATCH i-g-t v1] tests/kms_async_flips: Use lowest mode for crc subtest

["Naladala, Ramanaidu" <Ramanaidu.naladala@intel.com>]

Hi Santhosh,

Thanks for the clarification.

On 3/11/2026 11:19 AM, Reddy Guddati, Santhosh wrote:
> Hi Rama,
>
> On 10-03-2026 20:37, Naladala, Ramanaidu wrote:
>> Hi Santhosh,
>>
>> On 3/9/2026 1:54 PM, Santhosh Reddy Guddati wrote:
>>> Currently The CRC subtest uses mode[0] which maps to preffered high
>>> refresh mode. On panels with multiple modes, pick the lower mode to
>>> speed up crc test.
>>>
>>> Signed-off-by: Santhosh Reddy Guddati 
>>> <santhosh.reddy.guddati@intel.com>
>>> ---
>>>   tests/kms_async_flips.c | 15 +++++++++++++--
>>>   1 file changed, 13 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/tests/kms_async_flips.c b/tests/kms_async_flips.c
>>> index a42407363..8639e2299 100644
>>> --- a/tests/kms_async_flips.c
>>> +++ b/tests/kms_async_flips.c
>>> @@ -825,6 +825,17 @@ static void paint_fb(data_t *data, struct 
>>> igt_fb *fb,
>>>       }
>>>   }
>>> +static drmModeModeInfoPtr get_lower_mode_for_crc(igt_output_t *output)
>>> +{
>>> +    drmModeConnector *connector = output->config.connector;
>>> +
>>> +    igt_assert(connector->count_modes > 0);
Instead of simple assert, change to the igt_require_f with right message.
>>> +
>>> +    igt_sort_connector_modes(connector, sort_drm_modes_by_clk_asc);
>>> +
>>> +    return &connector->modes[0];
>>> +}
Imho, Rename the function name and move it into lib/igt_kms.c for future 
use.
>>> +
>>>   static void test_crc(data_t *data)
>>>   {
>>>       unsigned int frame = 0;
>>> @@ -834,8 +845,8 @@ static void test_crc(data_t *data)
>>>       igt_display_commit2(&data->display, data->display.is_atomic ? 
>>> COMMIT_ATOMIC : COMMIT_LEGACY);
>>> -    /* make things faster by using a smallish mode */
>>> -    mode = &data->output->config.connector->modes[0];
>>> +    /* make things faster by using a lower bandwidth mode */
>>> +    mode = get_lower_mode_for_crc(data->output);
>>
>> This optimization is for simulation? if yes, Add a check for 
>> simulation then change to lower mode. On Hardware it won't take much 
>> time. Why this time optimization required on hardware?
>>
>> is any issues seen?
>
> Thanks for the comment.
>
> This change is not for simulation.
>
> The purpose is to fix CRC subtest mode selection on panels with 
> multiple modes (especially when there are HRR modes). Earlier we used 
> `connector->modes[0]`, which can pick a high-refresh/high-bandwidth 
> mode (if modes[0] has highest) and make this test path more sensitive.
>
> Now we select a lower-bandwidth mode using `get_lower_mode_for_crc()`. 
> The async flip + CRC validation logic is unchanged. So this is a 
> focused fix to make the test stable on HRR panels, not a new behavior 
> change.
>
> In past , we have seen issues related to this and the test was handled 
> to adjust the criteria.
>
> https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/8247
>>
>>>       width = mode->hdisplay;
>>>       height = mode->vdisplay;
>