[PATCH 4.5 100/200] drm/i915: Force ringbuffers to not be at offset 0

4.5-stable review patch. If anyone has any objections, please let me know. -- From: Chris Wilson commit 1b3e885a05d4f0a35dde035724e7c6453d2cbe71 upstream. For reasons unknown Sandybridge GT1 (at least) will eventually hang when it encounters a ring

[PATCH 4.5 100/200] drm/i915: Force ringbuffers to not be at offset 0

4.5-stable review patch. If anyone has any objections, please let me know. -- From: Chris Wilson commit 1b3e885a05d4f0a35dde035724e7c6453d2cbe71 upstream. For reasons unknown Sandybridge GT1 (at least) will eventually hang when it encounters a ring wraparound at offset 0. The