[Intel-gfx] [PATCH 2/3] drm/i915: Complete requests in nop_submit_request

[Tvrtko Ursulin]

On 18/11/2016 09:37, Chris Wilson wrote:
> 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 at chris-wilson.co.uk>
> Cc: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
> ---
>  drivers/gpu/drm/i915/i915_gem.c | 2 ++
>  1 file changed, 2 insertions(+)
>
> diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> index 7b9f5b99b0f3..7037a8b26903 100644
> --- a/drivers/gpu/drm/i915/i915_gem.c
> +++ b/drivers/gpu/drm/i915/i915_gem.c
> @@ -2762,6 +2762,8 @@ 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);

Slight deja vu but not sure - we don't have a way of marking these as 
failed so what happens in practice here? This as at the point of no 
return, no replay, or allowing the context to recover or something?

>  }
>
>  static void i915_gem_cleanup_engine(struct intel_engine_cs *engine)
>

Regards,

Tvrtko