drm/i915/selftests: Skip live context execution test without logical …

…contexts

If the HW (or driver) doesn't support logical contexts, don't pretend we
gain anything from trying to execute GPU commands with them. At best it
reports -ENODEV, which is an unhelpful failure that we should just skip.

v2: Be more specific and check the driver/engine caps for logical (HW)
context support.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Matthew Auld <matthew.auld@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180706101923.28548-1-chris@chris-wilson.co.uk

drivers/gpu/drm/i915/selftests/i915_gem_context.c

@@ -336,11 +336,15 @@ static int igt_ctx_exec(void *arg)
 	bool first_shared_gtt = true;
 	int err = -ENODEV;
 
-	/* Create a few different contexts (with different mm) and write
+	/*
+	 * Create a few different contexts (with different mm) and write
 	 * through each ctx/mm using the GPU making sure those writes end
 	 * up in the expected pages of our obj.
 	 */
 
+	if (!DRIVER_CAPS(i915)->has_logical_contexts)
+		return 0;
+
 	file = mock_file(i915);
 	if (IS_ERR(file))
 		return PTR_ERR(file);
@@ -367,6 +371,9 @@ static int igt_ctx_exec(void *arg)
 		}
 
 		for_each_engine(engine, i915, id) {
+			if (!engine->context_size)
+				continue; /* No logical context support in HW */
+
 			if (!intel_engine_can_store_dword(engine))
 				continue;