[RFC PATCH v3 20/21] drm/ttm: Use drm_exec_trylock for bo initialization

[Thomas Hellström]

Buffer object initialization may be part of a drm_exec transaction.
Rather than using dma_resv_trylock, use drm_exec_trylock_obj().

RFC: This patch indicates to me that we should avoid the -ENOMEM failure
for drm_exec_trylock, Could probably use a sleeping lock here without
problems.

Cc: Christian König <christian.koe...@amd.com>
Cc: Somalapuram Amaranath <amaranath.somalapu...@amd.com>
Cc: Matthew Brost <matthew.br...@intel.com>
Cc: <dri-devel@lists.freedesktop.org>
Signed-off-by: Thomas Hellström <thomas.hellst...@linux.intel.com>
---
 drivers/gpu/drm/ttm/ttm_bo.c | 21 ++++++++++++++++-----
 1 file changed, 16 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/ttm/ttm_bo.c b/drivers/gpu/drm/ttm/ttm_bo.c
index 8706502edcb1..70af66b5b86e 100644
--- a/drivers/gpu/drm/ttm/ttm_bo.c
+++ b/drivers/gpu/drm/ttm/ttm_bo.c
@@ -942,10 +942,17 @@ int ttm_bo_init_reserved(struct ttm_device *bdev, struct 
ttm_buffer_object *bo,
        /* passed reservation objects should already be locked,
         * since otherwise lockdep will be angered in radeon.
         */
-       if (!resv)
-               WARN_ON(!dma_resv_trylock(bo->base.resv));
-       else
+       if (!resv) {
+               if (ctx->exec) {
+                       ret = drm_exec_trylock_obj(ctx->exec, &bo->base);
+                       if (ret)
+                               goto err_put;
+               } else {
+                       WARN_ON(!dma_resv_trylock(bo->base.resv));
+               }
+       } else {
                dma_resv_assert_held(resv);
+       }
 
        ret = ttm_bo_validate(bo, placement, ctx);
        if (unlikely(ret))
@@ -954,8 +961,12 @@ int ttm_bo_init_reserved(struct ttm_device *bdev, struct 
ttm_buffer_object *bo,
        return 0;
 
 err_unlock:
-       if (!resv)
-               dma_resv_unlock(bo->base.resv);
+       if (!resv) {
+               if (ctx->exec)
+                       drm_exec_unlock_obj(ctx->exec, &bo->base);
+               else
+                       dma_resv_unlock(bo->base.resv);
+       }
 
 err_put:
        ttm_bo_put(bo);
-- 
2.44.0