Re: [PATCH i-g-t 01/12] tests/amdgpu/amd_mode_switch: Prepare for returning NULL from igt_crtc_for_pipe()

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

On Wed, 18 Mar 2026, Harry Wentland <harry.wentland@amd.com> wrote:
> On 2026-03-18 14:01, Kamil Konieczny wrote:
>> Hi Jani,
>> On 2026-03-16 at 13:19:03 +0200, Jani Nikula wrote:
>>> After checking there are enough pipes, AMD should always have the
>>> CRTCs. Assert that the CRTC is valid.
>>>
>>> This prepares for returning NULL for invalid pipes from
>>> igt_crtc_for_pipe() by ensuring the test logic is sound.
>>>
>>> Signed-off-by: Jani Nikula <jani.nikula@intel.com>
>> 
>> +cc AMD devs
>> Cc: Aurabindo Pillai <aurabindo.pillai@amd.com>
>> Cc: Harry Wentland <harry.wentland@amd.com>
>> Cc: Vitaly Prosyak <vitaly.prosyak@amd.com>
>> 
>>> ---
>>>  tests/amdgpu/amd_mode_switch.c | 2 ++
>>>  1 file changed, 2 insertions(+)
>>>
>>> diff --git a/tests/amdgpu/amd_mode_switch.c b/tests/amdgpu/amd_mode_switch.c
>>> index 4da07c412996..ffa2952bb5c2 100644
>>> --- a/tests/amdgpu/amd_mode_switch.c
>>> +++ b/tests/amdgpu/amd_mode_switch.c
>>> @@ -98,6 +98,8 @@ static void run_mode_switch_first_last(data_t *data, int num_pipes)
>>>  	for (j = 0; j < num_pipes; j++) {
>>>  		igt_crtc_t *crtc = igt_crtc_for_pipe(display, j);
>>>  
>>> +		igt_assert_f(crtc->valid, "There is no pipe %s\n", kmstest_pipe_name(j));
>>> +
>
> Not sure I follow how this prepares for returning NULL
> from igt_crtc_for_pipe(). Wouldn't this do the opposite
> and hit a NULL pointer with crtc->valid if the function
> returns NULL?

Should've explained myself better.

Currently igt_crtc_for_pipe() always returns a non-NULL pointer to a
crtc, which may or may not be valid.

Asserting crtc->valid ensures the CRTC really is valid here.

When changing igt_crtc_for_pipe() to return NULL for !crtc->valid CRTCs,
we'd also change s/crtc->valid/crtc/g.

BR,
Jani.



>
> Harry
>
>>>  		output = data->output[j];
>>>  		if (!igt_output_is_connected(output))
>>>  			continue;
>>> -- 
>>> 2.47.3
>>>
>

-- 
Jani Nikula, Intel