Add get_safe_torch_device in policies

lerobot/scripts/eval.py

@@ -18,7 +18,7 @@ from lerobot.common.envs.factory import make_env
 from lerobot.common.logger import log_output_dir
 from lerobot.common.policies.abstract import AbstractPolicy
 from lerobot.common.policies.factory import make_policy
-from lerobot.common.utils import init_logging, set_seed
+from lerobot.common.utils import get_safe_torch_device, init_logging, set_seed
 
 
 def write_video(video_path, stacked_frames, fps):
@@ -35,7 +35,8 @@ def eval_policy(
     fps: int = 15,
     return_first_video: bool = False,
 ):
-    policy.eval()
+    if policy is not None:
+        policy.eval()
     start = time.time()
     sum_rewards = []
     max_rewards = []
@@ -55,7 +56,8 @@ def eval_policy(
         with torch.inference_mode():
             # TODO(alexander-soare): When `break_when_any_done == False` this rolls out for max_steps even when all
             # envs are done the first time. But we only use the first rollout. This is a waste of compute.
-            policy.clear_action_queue()
+            if policy is not None:
+                policy.clear_action_queue()
             rollout = env.rollout(
                 max_steps=max_steps,
                 policy=policy,
@@ -128,10 +130,8 @@ def eval(cfg: dict, out_dir=None):
 
     init_logging()
 
-    if cfg.device == "cuda":
-        assert torch.cuda.is_available()
-    else:
-        logging.warning("Using CPU, this will be slow.")
+    # Check device is available
+    get_safe_torch_device(cfg.device, log=True)
 
     torch.backends.cudnn.benchmark = True
     torch.backends.cuda.matmul.allow_tf32 = True