[Intel-gfx] [PATCH 5/9] drm/i915: Rename drm_gem_object_unreference in preparation for lockless free

[Chris Wilson]

On Wed, Jul 20, 2016 at 12:51:31PM +0100, Dave Gordon wrote:
> On 20/07/16 12:43, Joonas Lahtinen wrote:
> >On ke, 2016-07-20 at 09:59 +0100, Chris Wilson wrote:
> >
> >>diff --git a/drivers/gpu/drm/i915/intel_guc_loader.c b/drivers/gpu/drm/i915/intel_guc_loader.c
> >>index 605c69658d2c..75a1496ceb6f 100644
> >>--- a/drivers/gpu/drm/i915/intel_guc_loader.c
> >>+++ b/drivers/gpu/drm/i915/intel_guc_loader.c
> >>@@ -737,13 +737,15 @@ void intel_guc_fini(struct drm_device *dev)
> >>  	struct drm_i915_private *dev_priv = to_i915(dev);
> >>  	struct intel_guc_fw *guc_fw = &dev_priv->guc.guc_fw;
> >>
> >>+	if (!guc_fw->guc_fw_obj)
> >>+		return;
> >>+
> >
> >This is definitely not a mechanical change, should be split to separate
> >patch (maybe outside of this series too).
> >
> >With that split out,
> >
> >Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> >
> >Regards, Joonas
> >
> >>  	mutex_lock(&dev->struct_mutex);
> >>  	direct_interrupts_to_host(dev_priv);
> >>  	i915_guc_submission_disable(dev_priv);
> >>  	i915_guc_submission_fini(dev_priv);
> >>
> >>-	if (guc_fw->guc_fw_obj)
> >>-		drm_gem_object_unreference(&guc_fw->guc_fw_obj->base);
> >>+	i915_gem_object_put(guc_fw->guc_fw_obj);
> >>  	guc_fw->guc_fw_obj = NULL;
> >>  	mutex_unlock(&dev->struct_mutex);
> 
> In my version of this set of transformations, I allowed the
> reference-releasing function (equivalent to i915_gem_object_put()
> here) to be called with NULL as a parameter;
> drm_gem_object_unreference() can already handle NULL, and since we
> now guarantee gem-obj == NULL <=> i915-obj == NULL, it's safe to
> pass it though. That allows quite a few simplifications in various
> bits of cleanup code.

There are 3 places where this applies, 2 of which are inside the guc. It
is the guc that is where the coventions breakdown.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre