drm/i915: fix regression due to ba3d8d749b01548b9

We don't track gpu flush request in any special way. So even with
obj->write_domain == 0, a gpu flush might be outstanding but no
yet executed. Even worse, the latest request might use the object
only for reading. So and unconditional call to object_wait_rendering
is needed for !pipelined.

Hence revert that patch fully and untangle the flushing from the
synchronization again.

Reported-by: Keith Packard <keithp@keithp.com>
Tested-by: Keith Packard <keithp@keithp.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 92b097d..5e54821 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -38,8 +38,7 @@
 
 static uint32_t i915_gem_get_gtt_alignment(struct drm_gem_object *obj);
 
-static int i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj,
-                                                 bool pipelined);
+static int i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj);
 static void i915_gem_object_flush_gtt_write_domain(struct drm_gem_object *obj);
 static void i915_gem_object_flush_cpu_write_domain(struct drm_gem_object *obj);
 static int i915_gem_object_set_to_cpu_domain(struct drm_gem_object *obj,
@@ -2594,7 +2593,7 @@ i915_gem_object_put_fence_reg(struct drm_gem_object *obj,
        if (reg->gpu) {
                int ret;
 
-               ret = i915_gem_object_flush_gpu_write_domain(obj, true);
+               ret = i915_gem_object_flush_gpu_write_domain(obj);
                if (ret)
                        return ret;
 
@@ -2742,8 +2741,7 @@ i915_gem_clflush_object(struct drm_gem_object *obj)
 
 /** Flushes any GPU write domain for the object if it's dirty. */
 static int
-i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj,
-                                      bool pipelined)
+i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj)
 {
        struct drm_device *dev = obj->dev;
        uint32_t old_write_domain;
@@ -2762,10 +2760,7 @@ i915_gem_object_flush_gpu_write_domain(struct drm_gem_object *obj,
                                            obj->read_domains,
                                            old_write_domain);
 
-       if (pipelined)
-               return 0;
-
-       return i915_gem_object_wait_rendering(obj, true);
+       return 0;
 }
 
 /** Flushes the GTT write domain for the object if it's dirty. */
@@ -2826,18 +2821,15 @@ i915_gem_object_set_to_gtt_domain(struct drm_gem_object *obj, int write)
        if (obj_priv->gtt_space == NULL)
                return -EINVAL;
 
-       ret = i915_gem_object_flush_gpu_write_domain(obj, false);
+       ret = i915_gem_object_flush_gpu_write_domain(obj);
        if (ret != 0)
                return ret;
+       ret = i915_gem_object_wait_rendering(obj, true);
+       if (ret)
+               return ret;
 
        i915_gem_object_flush_cpu_write_domain(obj);
 
-       if (write) {
-               ret = i915_gem_object_wait_rendering(obj, true);
-               if (ret)
-                       return ret;
-       }
-
        old_write_domain = obj->write_domain;
        old_read_domains = obj->read_domains;
 
@@ -2875,7 +2867,7 @@ i915_gem_object_set_to_display_plane(struct drm_gem_object *obj,
        if (obj_priv->gtt_space == NULL)
                return -EINVAL;
 
-       ret = i915_gem_object_flush_gpu_write_domain(obj, true);
+       ret = i915_gem_object_flush_gpu_write_domain(obj);
        if (ret)
                return ret;
 
@@ -2924,9 +2916,12 @@ i915_gem_object_set_to_cpu_domain(struct drm_gem_object *obj, int write)
        uint32_t old_write_domain, old_read_domains;
        int ret;
 
-       ret = i915_gem_object_flush_gpu_write_domain(obj, false);
+       ret = i915_gem_object_flush_gpu_write_domain(obj);
        if (ret != 0)
                return ret;
+       ret = i915_gem_object_wait_rendering(obj, true);
+       if (ret)
+               return ret;
 
        i915_gem_object_flush_gtt_write_domain(obj);
 
@@ -2935,12 +2930,6 @@ i915_gem_object_set_to_cpu_domain(struct drm_gem_object *obj, int write)
         */
        i915_gem_object_set_to_full_cpu_read_domain(obj);
 
-       if (write) {
-               ret = i915_gem_object_wait_rendering(obj, true);
-               if (ret)
-                       return ret;
-       }
-
        old_write_domain = obj->write_domain;
        old_read_domains = obj->read_domains;
 
@@ -3205,9 +3194,13 @@ i915_gem_object_set_cpu_read_domain_range(struct drm_gem_object *obj,
        if (offset == 0 && size == obj->size)
                return i915_gem_object_set_to_cpu_domain(obj, 0);
 
-       ret = i915_gem_object_flush_gpu_write_domain(obj, false);
+       ret = i915_gem_object_flush_gpu_write_domain(obj);
        if (ret != 0)
                return ret;
+       ret = i915_gem_object_wait_rendering(obj, true);
+       if (ret)
+               return ret;
+
        i915_gem_object_flush_gtt_write_domain(obj);
 
        /* If we're already fully in the CPU read domain, we're done. */