| From | Greg Kroah-Hartman <> | Subject | [ 218/218] Revert: drm/i915: correctly order the ring init sequence | Date | Fri, 28 Sep 2012 13:17:15 -0700 |
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3.4-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 <herton.krzesinski@canonical.com> Cc: Andreas Sturmlechner <andreas.sturmlechner@gmail.com> Cc: Jani Nikula <jani.nikula@intel.com> Cc: Yang Guang <guang.a.yang@intel.com> Cc: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- drivers/gpu/drm/i915/intel_ringbuffer.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-)
--- 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 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 } } - /* 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);
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