[Intel-gfx] [PATCH 12/12] drm/i915: Add BKL asserts to get page helpers

[Tvrtko Ursulin]

On 02/02/16 11:39, Chris Wilson wrote:
> On Tue, Feb 02, 2016 at 11:06:30AM +0000, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>>
>> Purpose is catching illegal callers.
>>
>> v2: Replace WARN_ON with lockdep_assert_held. (Chris Wilson, Daniel Vetter)
>> v3: Moved under dedicated CONFIG_DRM_I915_DEBUG and back to WARN_ON.
>>
>> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
>> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
>> Cc: Chris Wilson <chris at chris-wilson.co.uk>
>> ---
>>   drivers/gpu/drm/i915/i915_drv.h | 3 +++
>>   1 file changed, 3 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
>> index 4ad025210416..6d34f74a5919 100644
>> --- a/drivers/gpu/drm/i915/i915_drv.h
>> +++ b/drivers/gpu/drm/i915/i915_drv.h
>> @@ -2933,6 +2933,9 @@ i915_gem_object_get_dirty_page(struct drm_i915_gem_object *obj, int n);
>>   static inline struct page *
>>   i915_gem_object_get_page(struct drm_i915_gem_object *obj, int n)
>>   {
>> +#ifdef CONFIG_DRM_I915_DEBUG
>> +	WARN_ON_ONCE(!mutex_is_locked(&obj->base.dev->struct_mutex));
>> +#endif
>
> But lockdep gives us useful debug information!

But you can't stick in a for loop. That applies to the previous patch so 
this one is consistent with what CONFIG_DRM_I915_DEBUG does.

Regards,

Tvrtko