drm/i915: Remove forced stop ring on suspend/unload

Before suspending (or unloading), we would first wait upon all rendering
to be completed and then disable the rings. This later step is a remanent
from DRI1 days when we did not use request tracking for all operations
upon the ring. Now that we are sure we are waiting upon the very last
operation by the engine, we can forgo clobbering the ring registers,
though we do keep the assert that the engine is indeed idle before
sleeping.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Reviewed-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1470388464-28458-5-git-send-email-chris@chris-wilson.co.uk

1 files changed, 0 insertions, 26 deletions

diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index a07da548ff49..309c5d9b1c57 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -760,31 +760,6 @@ void intel_execlists_cancel_requests(struct intel_engine_cs *engine)
 	}
 }
 
-void intel_logical_ring_stop(struct intel_engine_cs *engine)
-{
-	struct drm_i915_private *dev_priv = engine->i915;
-	int ret;
-
-	if (!intel_engine_initialized(engine))
-		return;
-
-	ret = intel_engine_idle(engine);
-	if (ret)
-		DRM_ERROR("failed to quiesce %s whilst cleaning up: %d\n",
-			  engine->name, ret);
-
-	/* TODO: Is this correct with Execlists enabled? */
-	I915_WRITE_MODE(engine, _MASKED_BIT_ENABLE(STOP_RING));
-	if (intel_wait_for_register(dev_priv,
-				    RING_MI_MODE(engine->mmio_base),
-				    MODE_IDLE, MODE_IDLE,
-				    1000)) {
-		DRM_ERROR("%s :timed out trying to stop ring\n", engine->name);
-		return;
-	}
-	I915_WRITE_MODE(engine, _MASKED_BIT_DISABLE(STOP_RING));
-}
-
 static int intel_lr_context_pin(struct i915_gem_context *ctx,
 				struct intel_engine_cs *engine)
 {
@@ -1717,7 +1692,6 @@ void intel_logical_ring_cleanup(struct intel_engine_cs *engine)
 	dev_priv = engine->i915;
 
 	if (engine->buffer) {
-		intel_logical_ring_stop(engine);
 		WARN_ON((I915_READ_MODE(engine) & MODE_IDLE) == 0);
 	}