From 446d14d4c51010379f7f12f3616773e7e7fb47d9 Mon Sep 17 00:00:00 2001 From: Greg Kroah-Hartman Date: Fri, 28 Sep 2012 09:06:10 -0700 Subject: [PATCH] Revert: drm/i915: correctly order the ring init sequence This reverts commit 57ecc93ce680b1ace1f9e79d588dabe32353202c which really is commit 0d8957c8a90bbb5d34fab9a304459448a5131e06 upstream as it has been reported to cause problems in the 3.4.y kernel series. Reported-by: Herton Ronaldo Krzesinski Cc: Andreas Sturmlechner Cc: Jani Nikula Cc: Yang Guang Cc: Daniel Vetter Signed-off-by: Greg Kroah-Hartman --- drivers/gpu/drm/i915/intel_ringbuffer.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 12a9e5f..302d3d5 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -258,6 +258,8 @@ static int init_ring_common(struct intel_ring_buffer *ring) I915_WRITE_HEAD(ring, 0); ring->write_tail(ring, 0); + /* Initialize the ring. */ + I915_WRITE_START(ring, obj->gtt_offset); head = I915_READ_HEAD(ring) & HEAD_ADDR; /* G45 ring initialization fails to reset head to zero */ @@ -283,11 +285,6 @@ static int init_ring_common(struct intel_ring_buffer *ring) } } - /* Initialize the ring. This must happen _after_ we've cleared the ring - * registers with the above sequence (the readback of the HEAD registers - * also enforces ordering), otherwise the hw might lose the new ring - * register values. */ - I915_WRITE_START(ring, obj->gtt_offset); I915_WRITE_CTL(ring, ((ring->size - PAGE_SIZE) & RING_NR_PAGES) | RING_VALID); -- 2.7.4