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

[Dave Gordon]

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.

.Dave.