Re: [PATCH v3] drm/i915: Small compaction of the engine init code

Tvrtko Ursulin
2016-06-23T11:46:43Z

On 23/06/16 12:25, Chris Wilson wrote:
> On Thu, Jun 23, 2016 at 12:12:29PM +0100, Tvrtko Ursulin wrote:
>> From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
>>
>> Effectively removes one layer of indirection between the mask of
>> possible engines and the engine constructors. Instead of spelling
>> out in code the mapping of HAS_<engine> to constructors, makes
>> more use of the recently added data driven approach by putting
>> engine constructor vfuncs into the table as well.
>>
>> Effect is fewer lines of source and smaller binary.
>>
>> At the same time simplify the error handling since engine
>> destructors can run on unitialized engines anyway.
>>
>> Similar approach could be done for legacy submission is wanted.
>>
>> v2: Removed ugly BUILD_BUG_ONs in favour of newly introduced
>> ENGINE_MASK and HAS_ENGINE macros.
>> Also removed the forward declarations by shuffling functions
>> around.
>>
>> v3: Warn when logical_rings table does not contain enough data
>> and disable the engines which could not be initialized.
>> (Chris Wilson)
>
> I was happy with the BUILD_BUG suggestion :)

I've changed my mind later. :)

>> + for (i = 0;
>> + i < I915_NUM_ENGINES && i < ARRAY_SIZE(logical_rings); i++) {
>
> HAS_ENGINE() == false if i >= I915_NUM_ENGINES

Don't follow. :) Why is v3 not good enough?

Regards,

Tvrtko