drm/i915: Avoid early GPU idling due to race with new request

There is a small race where a new request can be submitted and retired
after the idle worker started to run which leads to idling the GPU too
early. Fix this by deferring the idling to the pending instance of the
worker.

This scenario was pointed out by Chris.

Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Imre Deak <imre.deak@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: http://patchwork.freedesktop.org/patch/msgid/1478510405-11799-2-git-send-email-imre.deak@intel.com
This commit is contained in:
Imre Deak 2016-11-07 11:20:03 +02:00
parent 5bd11a34e4
commit 93c97dc17f
1 changed files with 7 additions and 0 deletions

View File

@ -2766,6 +2766,13 @@ i915_gem_idle_work_handler(struct work_struct *work)
goto out_rearm;
}
/*
* New request retired after this work handler started, extend active
* period until next instance of the work.
*/
if (work_pending(work))
goto out_unlock;
if (dev_priv->gt.active_requests)
goto out_unlock;