drm/i915: Complete requests in nop_submit_request

Since the submit/execute split in commit d55ac5bf97c6 ("drm/i915: Defer
transfer onto execution timeline to actual hw submission") the
global seqno advance was deferred until the submit_request callback.
After wedging the GPU, we were installing a nop_submit_request handler
(to avoid waking up the dead hw) but I had missed converting this over
to the new scheme. Under the new scheme, we have to explicitly call
i915_gem_submit_request() from the submit_request handler to mark the
request as on the hardware. If we don't the request is always pending,
and any waiter will continue to wait indefinitely and hangcheck will not
be able to resolve the lockup.

References: https://bugs.freedesktop.org/show_bug.cgi?id=98748
Testcase: igt/gem_eio/in-flight
Fixes: d55ac5bf97c6 ("drm/i915: Defer transfer onto execution timeline to actual hw submission")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/20161122144121.7379-3-chris@chris-wilson.co.uk
(cherry picked from commit 3dcf93f7f23a61e867a5ccadaf651cb2d29229fd)
Signed-off-by: Jani Nikula <jani.nikula@intel.com>

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 902fa427c19612bac15dd0540f4ebde846da7943..d0dcaf35b4298c7c58440881597b3ad4b76522f0 100644 (file)
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -2764,6 +2764,8 @@ void i915_gem_reset(struct drm_i915_private *dev_priv)
 
 static void nop_submit_request(struct drm_i915_gem_request *request)
 {
+       i915_gem_request_submit(request);
+       intel_engine_init_global_seqno(request->engine, request->global_seqno);
 }
 
 static void i915_gem_cleanup_engine(struct intel_engine_cs *engine)