Commit c604d319 authored by Matthew Auld's avatar Matthew Auld Committed by Christian König
Browse files

drm/gem-vram: handle NULL bo->resource in move callback 



The ttm BO now initially has NULL bo->resource, and leaves the driver
the handle that. However it looks like we forgot to handle that for
ttm_bo_move_memcpy() users, like with vram-gem, since it just silently
returns zero. This seems to then trigger warnings like:

WARNING: CPU: 0 PID: 1 at drivers/gpu/drm/drm_gem_vram_helper.c:255 drm_gem_vram_offset (??:?)

Fix this by calling move_null() if the new resource is TTM_PL_SYSTEM,
otherwise do the multi-hop sequence to ensure can safely call into
ttm_bo_move_memcpy(), since it might also need to clear the memory.
This should give the same behaviour as before.

While we are here let's also treat calling ttm_bo_move_memcpy() with
NULL bo->resource as programmer error, where expectation is that upper
layers should now handle it.

Fixes: 18025378 ("drm/ttm: stop allocating dummy resources during BO creation")
Signed-off-by: default avatarMatthew Auld <matthew.auld@intel.com>
Cc: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230208145319.397235-1-matthew.auld@intel.com


Acked-by: default avatarChristian König <christian.koenig@amd.com>
Signed-off-by: default avatarChristian König <christian.koenig@amd.com>
parent 4d5a2cce

drivers/gpu/drm/drm_gem_vram_helper.c

+11 −0
Original line number Diff line number Diff line
@@ -916,6 +916,17 @@ static int bo_driver_move(struct ttm_buffer_object *bo, 
{

	struct drm_gem_vram_object *gbo;



	if (!bo->resource) {

		if (new_mem->mem_type != TTM_PL_SYSTEM) {

			hop->mem_type = TTM_PL_SYSTEM;

			hop->flags = TTM_PL_FLAG_TEMPORARY;

			return -EMULTIHOP;

		}



		ttm_bo_move_null(bo, new_mem);

		return 0;

	}



	gbo = drm_gem_vram_of_bo(bo);



	return drm_gem_vram_bo_driver_move(gbo, evict, ctx, new_mem);

drivers/gpu/drm/ttm/ttm_bo_util.c

+2 −2
Original line number Diff line number Diff line
@@ -157,8 +157,8 @@ int ttm_bo_move_memcpy(struct ttm_buffer_object *bo, 
	bool clear;

	int ret = 0;



	if (!src_mem)

		return 0;

	if (WARN_ON(!src_mem))

		return -EINVAL;



	src_man = ttm_manager_type(bdev, src_mem->mem_type);

	if (ttm && ((ttm->page_flags & TTM_TT_FLAG_SWAPPED) ||