drm/i915: Check to see if we've pinned all available fences

We need to check and report if there are no available fences - or else we
spin endlessly waiting for a buffer to magically unpin itself.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Eric Anholt <eric@anholt.net>
This commit is contained in:
Chris Wilson 2009-02-11 14:26:46 +00:00 committed by Eric Anholt
parent 22c344e9a0
commit fc7170ba28

View File

@ -1557,7 +1557,8 @@ i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write)
struct drm_i915_private *dev_priv = dev->dev_private;
struct drm_i915_gem_object *obj_priv = obj->driver_private;
struct drm_i915_fence_reg *reg = NULL;
int i, ret;
struct drm_i915_gem_object *old_obj_priv = NULL;
int i, ret, avail;
switch (obj_priv->tiling_mode) {
case I915_TILING_NONE:
@ -1581,17 +1582,24 @@ i915_gem_object_get_fence_reg(struct drm_gem_object *obj, bool write)
/* First try to find a free reg */
try_again:
avail = 0;
for (i = dev_priv->fence_reg_start; i < dev_priv->num_fence_regs; i++) {
reg = &dev_priv->fence_regs[i];
if (!reg->obj)
break;
old_obj_priv = reg->obj->driver_private;
if (!old_obj_priv->pin_count)
avail++;
}
/* None available, try to steal one or wait for a user to finish */
if (i == dev_priv->num_fence_regs) {
struct drm_i915_gem_object *old_obj_priv = NULL;
loff_t offset;
if (avail == 0)
return -ENOMEM;
/* Could try to use LRU here instead... */
for (i = dev_priv->fence_reg_start;
i < dev_priv->num_fence_regs; i++) {