[PATCH i-g-t] lib/igt_kms: Update igt_fit_modes_in_bw to add legacy commit check

[Karthik B S]

Hi Peter,

On 7/11/2025 1:20 PM, Peter Senna Tschudin wrote:
> Hi Karthik,
>
> On 7/10/2025 9:46 PM, Karthik B S wrote:
>> Currently igt_fit_modes_in_bw is only checking for atomic commit but the
>> igt_override_all_active_output_modes_to_fit_bw function which it is
>> wrapping actually has support for legacy commit as well.
>>
>> To handle this, add support for legacy commit check as well.
>>
>> Signed-off-by: Karthik B S <karthik.b.s at intel.com>
>> ---
>>   lib/igt_kms.c | 10 +++++++---
>>   1 file changed, 7 insertions(+), 3 deletions(-)
>>
>> diff --git a/lib/igt_kms.c b/lib/igt_kms.c
>> index 84ba1635c..7dee8ab2c 100644
>> --- a/lib/igt_kms.c
>> +++ b/lib/igt_kms.c
>> @@ -5061,9 +5061,13 @@ bool igt_fit_modes_in_bw(igt_display_t *display)
>>   {
>>   	int ret;
>>   
>> -	ret = igt_display_try_commit_atomic(display,
>> -					    DRM_MODE_ATOMIC_TEST_ONLY |
>> -					    DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>> +	if (display->is_atomic)
>> +		ret = igt_display_try_commit_atomic(display,
>> +						    DRM_MODE_ATOMIC_TEST_ONLY |
>> +						    DRM_MODE_ATOMIC_ALLOW_MODESET, NULL);
>> +	else
>> +		ret = igt_display_try_commit2(display, COMMIT_LEGACY);
>> +
>>   	if (ret != 0) {
>>   		bool found;
>>   
> I guess the function description needs attention. Currently it is "Tries
> atomic TEST_ONLY commit; if it fails, overrides output modes to fit
> bandwidth."
>
> Now that it also tries the COMMIT_LEGACY, what about:
>
> "Attempts to commit the current display configuration. For atomic
> displays, performs an atomic TEST_ONLY commit; for legacy non-atomic
> displays, performs a legacy commit. If the commit fails, attempts to
> override all active output modes to fit within available bandwidth."
Thank you for catching this. Will update this.
>
> Reviewed-by: Peter Senna Tschudin <peter.senna at linux.intel.com>

Thanks for the rb.

Thanks,
Karthik.B.S