1 files changed, 20 insertions, 3 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 472939f5c18f..d0ef50bf930a 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -1677,9 +1677,26 @@ static int switch_context(struct i915_request *rq)
         GEM_BUG_ON(HAS_EXECLISTS(rq->i915));
 
         if (ppgtt) {
-                ret = load_pd_dir(rq, ppgtt);
-                if (ret)
-                        goto err;
+                int loops;
+
+                /*
+                 * Baytail takes a little more convincing that it really needs
+                 * to reload the PD between contexts. It is not just a little
+                 * longer, as adding more stalls after the load_pd_dir (i.e.
+                 * adding a long loop around flush_pd_dir) is not as effective
+                 * as reloading the PD umpteen times. 32 is derived from
+                 * experimentation (gem_exec_parallel/fds) and has no good
+                 * explanation.
+                 */
+                loops = 1;
+                if (engine->id == BCS && IS_VALLEYVIEW(engine->i915))
+                        loops = 32;
+
+                do {
+                        ret = load_pd_dir(rq, ppgtt);
+                        if (ret)
+                                goto err;
+                } while (--loops);
 
                 if (intel_engine_flag(engine) & ppgtt->pd_dirty_rings) {
                         unwind_mm = intel_engine_flag(engine);