[PATCH 2/2] drm/ttm: revert "stop allocating dummy resources during BO creation"

[Christian König]

Am 25.01.23 um 17:13 schrieb Matthew Auld:
> On Wed, 25 Jan 2023 at 15:50, Christian König
> <ckoenig.leichtzumerken at gmail.com> wrote:
>> This reverts commit 00984ad39599bb2a1e6ec5d4e9c75a749f7f45c9.
>>
>> It seems to still breka i915.
> We also need to revert the third patch:
>
> b49323aa35d5 drm/ttm: prevent moving of pinned BOs
>
> It introduces the side effect of no longer calling tt_create(true) in
> ttm_bo_validate(), and I'm 99% sure that will break object clearing.
> We rely on having a ttm_tt for the initial dummy placement, with
> FLAG_ZERO_ALLOC set if clear is needed. Also I'm not sure who even
> creates the ttm_tt now, if ttm_bo_validate() doesn't, and we don't
> have the dummy move, like with this patch.

Oh, yes of course. Can I add your Acked-by to reverting all three?

Thanks,
Christian.

>
>> Signed-off-by: Christian König <christian.koenig at amd.com>
>> ---
>>   drivers/gpu/drm/ttm/ttm_bo.c | 7 +++++++
>>   1 file changed, 7 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
>> index 33471e363ff4..9baccb2f6e99 100644
>> --- a/drivers/gpu/drm/ttm/ttm_bo.c
>> +++ b/drivers/gpu/drm/ttm/ttm_bo.c
>> @@ -957,6 +957,7 @@ int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
>>                           struct sg_table *sg, struct dma_resv *resv,
>>                           void (*destroy) (struct ttm_buffer_object *))
>>   {
>> +       static const struct ttm_place sys_mem = { .mem_type = TTM_PL_SYSTEM };
>>          int ret;
>>
>>          kref_init(&bo->kref);
>> @@ -973,6 +974,12 @@ int ttm_bo_init_reserved(struct ttm_device *bdev, struct ttm_buffer_object *bo,
>>                  bo->base.resv = &bo->base._resv;
>>          atomic_inc(&ttm_glob.bo_count);
>>
>> +       ret = ttm_resource_alloc(bo, &sys_mem, &bo->resource);
>> +       if (unlikely(ret)) {
>> +               ttm_bo_put(bo);
>> +               return ret;
>> +       }
>> +
>>          /*
>>           * For ttm_bo_type_device buffers, allocate
>>           * address space from the device.
>> --
>> 2.34.1
>>