Re: [i-g-t] tests/core_hotunplug: Open render capable DRM device

["Randhawa, Jagmeet" <jagmeet.randhawa@intel.com>]

Hello Kamil,


For this test file, All subtests use render device for health checks. 
Because of that,

selecting a render capable device up front seems like the most direct 
way to establish test

precondition and avoid accidentally selecting a card-only driver such as 
simpledrm.


Adding simpledrm to the list of known/blocked drivers could work, but we 
would still need

additional logic to continue scanning and select next suitable driver. 
Selecting a render-capable

device first naturally ensures we pick a device that exposes a render 
node and avoids the simpledrm

case without adding special handling for a specific driver.


There is no public GitLab issue for this, failure observed internally.

On 3/4/2026 5:56 AM, Kamil Konieczny wrote:
> Hi Jagmeet,
> On 2026-03-04 at 06:53:32 +0800, Jagmeet Randhawa wrote:
>> The test may select simpledrm when opening DRIVER_ANY,
>> which does not expose a render node. This causes the
>> later render open to fail.
>>
>> Open a render capable device initially using
>> __drm_open_driver_render(DRIVER_ANY) to avoid
>> selecting simpledrm.
> This is strange, as this test assumes card open and then tries
> uses render for verification so I am not sure if you could
> start with render. Adding Janusz to Cc.
>
> Could you also add links to issues on GitLab, if there are any?
>
> Other idea to solve this would be to add simpledrm to known
> drivers and a blocked ones, like VGEM.
>
> Regards,
> Kamil
>
> Cc: Janusz Krzysztofik <janusz.krzysztofik@linux.intel.com>
> Cc: "Zbigniew Kempczyński" <zbigniew.kempczynski@intel.com>
>
>> Signed-off-by: Jagmeet Randhawa <jagmeet.randhawa@intel.com>
>> ---
>>   tests/core_hotunplug.c | 4 ++--
>>   1 file changed, 2 insertions(+), 2 deletions(-)
>>
>> diff --git a/tests/core_hotunplug.c b/tests/core_hotunplug.c
>> index 7c9dae1bf..3a612fce2 100644
>> --- a/tests/core_hotunplug.c
>> +++ b/tests/core_hotunplug.c
>> @@ -696,8 +696,8 @@ int igt_main()
>>   		int fd_drm;
>>   		char driver[32] = {};
>>   
>> -		fd_drm = __drm_open_driver(DRIVER_ANY);
>> -		igt_skip_on_f(fd_drm < 0, "No known DRM device found\n");
>> +		fd_drm = __drm_open_driver_render(DRIVER_ANY);
>> +		igt_skip_on_f(fd_drm < 0, "No known DRM render device found\n");
>>   
>>   		priv.chipset = drm_get_chipset(fd_drm);
>>   		/* Make sure it opens the same driver */
>> -- 
>> 2.52.0
>>