[Intel-gfx] [PATCH 2/2] drm/i915: Remove impossibe checks from i915_gem_request_add_to_client

[Chris Wilson]

On Wed, Mar 23, 2016 at 03:15:03PM +0000, Tvrtko Ursulin wrote:
> From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> 
> There is only one caller of this functions which calls it under
> strictly defined conditions. Error checking and return value
> can be removed.
> 
> Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
> BTW it looks like the whole point of this request list is to implement
> the throttle ioctl? Looks like a strange ioctl with a fixed 20ms criteria,
> could it be re-implemented somehow without having to have this list?
> 
> Does it have to be per-client or could it wait for any requests on any
> engine emitted 20ms ago?

It is per-client, and I long wished the 20ms wasn't defined by the ABI.

What I proposed doing is this:

https://cgit.freedesktop.org/~ickle/linux-2.6/commit/?h=breadcrumbs&id=e33947505b54582964c8c202b22f88fc5705f484

Please note that this also fixes a race condition I've seen in the wild.
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre