1 files changed, 11 insertions, 7 deletions

diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
index 45ce45a5e122..9121646d7c4d 100644
--- a/drivers/gpu/drm/i915/intel_ringbuffer.c
+++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
@@ -968,7 +968,7 @@ static int gen9_init_workarounds(struct intel_engine_cs *ring)
 
         /* WaForceContextSaveRestoreNonCoherent:skl,bxt */
         tmp = HDC_FORCE_CONTEXT_SAVE_RESTORE_NON_COHERENT;
-        if (IS_SKL_REVID(dev, SKL_REVID_F0, SKL_REVID_F0) ||
+        if (IS_SKL_REVID(dev, SKL_REVID_F0, REVID_FOREVER) ||
             IS_BXT_REVID(dev, BXT_REVID_B0, REVID_FOREVER))
                 tmp |= HDC_FORCE_CSR_NON_COHERENT_OVR_DISABLE;
         WA_SET_BIT_MASKED(HDC_CHICKEN0, tmp);
@@ -1085,7 +1085,8 @@ static int skl_init_workarounds(struct intel_engine_cs *ring)
                 WA_SET_BIT_MASKED(HIZ_CHICKEN,
                                   BDW_HIZ_POWER_COMPILER_CLOCK_GATING_DISABLE);
 
-        if (IS_SKL_REVID(dev, 0, SKL_REVID_F0)) {
+        /* This is tied to WaForceContextSaveRestoreNonCoherent */
+        if (IS_SKL_REVID(dev, 0, REVID_FOREVER)) {
                 /*
                  *Use Force Non-Coherent whenever executing a 3D context. This
                  * is a workaround for a possible hang in the unlikely event
@@ -2090,10 +2091,12 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
 {
         struct drm_i915_private *dev_priv = to_i915(dev);
         struct drm_i915_gem_object *obj = ringbuf->obj;
+        /* Ring wraparound at offset 0 sometimes hangs. No idea why. */
+        unsigned flags = PIN_OFFSET_BIAS | 4096;
         int ret;
 
         if (HAS_LLC(dev_priv) && !obj->stolen) {
-                ret = i915_gem_obj_ggtt_pin(obj, PAGE_SIZE, 0);
+                ret = i915_gem_obj_ggtt_pin(obj, PAGE_SIZE, flags);
                 if (ret)
                         return ret;
 
@@ -2109,7 +2112,8 @@ int intel_pin_and_map_ringbuffer_obj(struct drm_device *dev,
                         return -ENOMEM;
                 }
         } else {
-                ret = i915_gem_obj_ggtt_pin(obj, PAGE_SIZE, PIN_MAPPABLE);
+                ret = i915_gem_obj_ggtt_pin(obj, PAGE_SIZE,
+                                            flags | PIN_MAPPABLE);
                 if (ret)
                         return ret;
 
@@ -2454,11 +2458,11 @@ static int __intel_ring_prepare(struct intel_engine_cs *ring, int bytes)
                 if (unlikely(total_bytes > remain_usable)) {
                         /*
                          * The base request will fit but the reserved space
-                         * falls off the end. So only need to to wait for the
-                         * reserved size after flushing out the remainder.
+                         * falls off the end. So don't need an immediate wrap
+                         * and only need to effectively wait for the reserved
+                         * size space from the start of ringbuffer.
                          */
                         wait_bytes = remain_actual + ringbuf->reserved_size;
-                        need_wrap = true;
                 } else if (total_bytes > ringbuf->space) {
                         /* No wrapping required, just waiting. */
                         wait_bytes = total_bytes;