[Intel-gfx] [PATCH v5 07/11] drm/i915: tidy initialisation failure paths (legacy, part 3)

[Dave Gordon]

intel_cleanup_ring_buffer() contains one low-level register access,
which is not really appropriate for its level of abstraction.

It calls intel_stop_ring_buffer() which then calls stop_ring() -- which
is the level that deals with h/w registers -- then reads a GEN-specific
register to see whether the ring is actually now idle. It only prints a
WARNING, though, and doesn't actually refrain from continuing even if
the test fails!

So, let's move the register-level check and WARNING down into the
low-level function that's already doing register access. If we wanted
to, we could pass a pass/fail status back, but since the high-level
code continues anyway, there's no reason to at present.

As a bonus, apart from fixing the lavering violation, moving the code
lets us eliminate the implicitly-used local 'dev_priv' from the caller.

Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
---
 drivers/gpu/drm/i915/intel_ringbuffer.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 284da10..b47d140 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -551,6 +551,8 @@ static bool stop_ring(struct intel_engine_cs *ring)
 		I915_WRITE_MODE(ring, _MASKED_BIT_DISABLE(STOP_RING));
 	}
 
+	WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
+
 	return (I915_READ_HEAD(ring) & HEAD_ADDR) == 0;
 }
 
@@ -2260,17 +2262,11 @@ static int intel_init_ring_buffer(struct drm_device *dev,
 
 void intel_cleanup_ring_buffer(struct intel_engine_cs *ring)
 {
-	struct drm_i915_private *dev_priv;
-
 	if (!intel_ring_initialized(ring))
 		return;
 
-	dev_priv = to_i915(ring->dev);
-
 	if (ring->buffer) {
 		intel_stop_ring_buffer(ring);
-		WARN_ON(!IS_GEN2(ring->dev) && (I915_READ_MODE(ring) & MODE_IDLE) == 0);
-
 		intel_unpin_ringbuffer_obj(ring->buffer);
 		intel_ringbuffer_free(ring->buffer);
 		ring->buffer = NULL;
-- 
1.9.1