intel: Don't call the SW_FINISH ioctl unless a CPU-mapped write was done.

Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>

diff --git a/intel/intel_bufmgr_gem.c b/intel/intel_bufmgr_gem.c
index 94549f8..cebf732 100644 (file)
--- a/intel/intel_bufmgr_gem.c
+++ b/intel/intel_bufmgr_gem.c
@@ -196,6 +196,9 @@ struct _drm_intel_bo_gem {
         * relocations.
         */
        int reloc_tree_fences;
+
+       /** Flags that we may need to do the SW_FINSIH ioctl on unmap. */
+       bool mapped_cpu_write;
 };
 
 static unsigned int
@@ -1051,6 +1054,9 @@ static int drm_intel_gem_bo_map(drm_intel_bo *bo, int write_enable)
                    strerror(errno));
        }
 
+       if (write_enable)
+               bo_gem->mapped_cpu_write = true;
+
        pthread_mutex_unlock(&bufmgr_gem->lock);
 
        return 0;
@@ -1148,21 +1154,27 @@ static int drm_intel_gem_bo_unmap(drm_intel_bo *bo)
        drm_intel_bufmgr_gem *bufmgr_gem = (drm_intel_bufmgr_gem *) bo->bufmgr;
        drm_intel_bo_gem *bo_gem = (drm_intel_bo_gem *) bo;
        struct drm_i915_gem_sw_finish sw_finish;
-       int ret;
+       int ret = 0;
 
        if (bo == NULL)
                return 0;
 
        pthread_mutex_lock(&bufmgr_gem->lock);
 
-       /* Cause a flush to happen if the buffer's pinned for scanout, so the
-        * results show up in a timely manner.
-        */
-       sw_finish.handle = bo_gem->gem_handle;
-       ret = drmIoctl(bufmgr_gem->fd,
-                      DRM_IOCTL_I915_GEM_SW_FINISH,
-                      &sw_finish);
-       ret = ret == -1 ? -errno : 0;
+       if (bo_gem->mapped_cpu_write) {
+               /* Cause a flush to happen if the buffer's pinned for
+                * scanout, so the results show up in a timely manner.
+                * Unlike GTT set domains, this only does work if the
+                * buffer should be scanout-related.
+                */
+               sw_finish.handle = bo_gem->gem_handle;
+               ret = drmIoctl(bufmgr_gem->fd,
+                              DRM_IOCTL_I915_GEM_SW_FINISH,
+                              &sw_finish);
+               ret = ret == -1 ? -errno : 0;
+
+               bo_gem->mapped_cpu_write = false;
+       }
 
        bo->virtual = NULL;
        pthread_mutex_unlock(&bufmgr_gem->lock);