drm/i915: Install fence register for tiled scanout on i915
With the work by Jesse Barnes to eliminate allocation of fences during
execbuffer, it becomes possible to write to the scan-out buffer with it
never acquiring a fence (simply by only ever writing to the object using
tiled GPU commands and never writing to it via the GTT). So for pre-i965
chipsets which require fenced access for tiled scan-out buffers, we need
to obtain a fence register.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c
index 028f5b6..3e1c781 100644
--- a/drivers/gpu/drm/i915/intel_display.c
+++ b/drivers/gpu/drm/i915/intel_display.c
@@ -828,19 +828,31 @@
}
mutex_lock(&dev->struct_mutex);
- ret = i915_gem_object_pin(intel_fb->obj, alignment);
+ ret = i915_gem_object_pin(obj, alignment);
if (ret != 0) {
mutex_unlock(&dev->struct_mutex);
return ret;
}
- ret = i915_gem_object_set_to_gtt_domain(intel_fb->obj, 1);
+ ret = i915_gem_object_set_to_gtt_domain(obj, 1);
if (ret != 0) {
- i915_gem_object_unpin(intel_fb->obj);
+ i915_gem_object_unpin(obj);
mutex_unlock(&dev->struct_mutex);
return ret;
}
+ /* Pre-i965 needs to install a fence for tiled scan-out */
+ if (!IS_I965G(dev) &&
+ obj_priv->fence_reg == I915_FENCE_REG_NONE &&
+ obj_priv->tiling_mode != I915_TILING_NONE) {
+ ret = i915_gem_object_get_fence_reg(obj);
+ if (ret != 0) {
+ i915_gem_object_unpin(obj);
+ mutex_unlock(&dev->struct_mutex);
+ return ret;
+ }
+ }
+
dspcntr = I915_READ(dspcntr_reg);
/* Mask out pixel format bits in case we change it */
dspcntr &= ~DISPPLANE_PIXFORMAT_MASK;
@@ -860,7 +872,7 @@
break;
default:
DRM_ERROR("Unknown color depth\n");
- i915_gem_object_unpin(intel_fb->obj);
+ i915_gem_object_unpin(obj);
mutex_unlock(&dev->struct_mutex);
return -EINVAL;
}