[PATCH v10 4/9] drm/ttm/tests: Add tests with mock resource managers

[Karolina Stolarek]

On 10.04.2024 16:24, Matthew Auld wrote:
> On 22/03/2024 14:29, Karolina Stolarek wrote:
>> +static const struct ttm_bo_validate_test_case ttm_mem_type_cases[] = {
>> +    {
>> +        .description = "System manager",
>> +        .mem_type = TTM_PL_SYSTEM,
>> +    },
>> +    {
>> +        .description = "VRAM manager",
>> +        .mem_type = TTM_PL_SYSTEM,
> 
> This should be PL_VRAM ?

Facepalm
Yes, indeed it should be VRAM, well spotted.

(...)

>> diff --git a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c 
>> b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>> index c75de24de783..83a942919cc8 100644
>> --- a/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>> +++ b/drivers/gpu/drm/ttm/tests/ttm_kunit_helpers.c
>> @@ -27,8 +27,43 @@ static int mock_move(struct ttm_buffer_object *bo, 
>> bool evict,
>>                struct ttm_resource *new_mem,
>>                struct ttm_place *hop)
>>   {
>> -    bo->resource = new_mem;
>> -    return 0;
>> +    struct ttm_resource *old_mem = bo->resource;
>> +    int ret;
>> +
>> +    if (!old_mem || (old_mem->mem_type == TTM_PL_SYSTEM && !bo->ttm)) {
>> +        ttm_bo_move_null(bo, new_mem);
>> +        return 0;
>> +    }
>> +
>> +    /* Dummy multihop */
>> +    if (bo->resource->mem_type == TTM_PL_VRAM &&
>> +        new_mem->mem_type == TTM_PL_MULTIHOP) {
> 
> Do we need this dummy multi-hop type? Is not possible to just do this 
> for SYSTEM -> TT -> VRAM and/or VRAM -> TT -> SYSTEM, that's at least 
> the normal flow which requires the multi-hop sequence in the middle.

Hmm, back in the day it made sense to me to do it this way, but I agree,
using TT domain here would be a better solution. I'll try to rewrite it
and drop multihop type altogether.

Many thanks,
Karolina