Quoting Mika Kuoppala (2017-11-03 14:03:25)
> Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> writes:
>
> > In the next few patches, we will have a hard requirement that we emit a
> > context-switch to the perma-pinned i915->kernel_context (so that we can
> > save the HW state using that context-switch). As the first context
> > itself may be classed as a kernel context, we want to be explicit in our
> > comparison. For an extra-layer of finesse, we can check the last
> > unretired context on the engine; as well as the last retired context
> > when idle.
> >
> > v2: verbose verbosity
> > v3: Always force the switch, even when the engine is idle, and update
> > the assert that this happens before suspend.
> >
> > Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
> > Cc: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
> > Reviewed-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx> #v1
> > ---
> > drivers/gpu/drm/i915/i915_gem.c | 10 ++++++----
> > drivers/gpu/drm/i915/intel_engine_cs.c | 26 ++++++++++++++++++++++++--
> > 2 files changed, 30 insertions(+), 6 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
> > index 9470ba0c1930..fe312ab3b664 100644
> > --- a/drivers/gpu/drm/i915/i915_gem.c
> > +++ b/drivers/gpu/drm/i915/i915_gem.c
> > @@ -4687,14 +4687,16 @@ void __i915_gem_object_release_unless_active(struct drm_i915_gem_object *obj)
> > i915_gem_object_put(obj);
> > }
> >
> > -static void assert_kernel_context_is_current(struct drm_i915_private *dev_priv)
> > +static void assert_kernel_context_is_current(struct drm_i915_private *i915)
> > {
> > + struct i915_gem_context *kernel_context = i915->kernel_context;
> > struct intel_engine_cs *engine;
> > enum intel_engine_id id;
> >
> > - for_each_engine(engine, dev_priv, id)
> > - GEM_BUG_ON(engine->last_retired_context &&
> > - !i915_gem_context_is_kernel(engine->last_retired_context));
> > + for_each_engine(engine, i915, id) {
> > + GEM_BUG_ON(__i915_gem_active_peek(&engine->timeline->last_request));
>
> It could be that we have a active request for kernel context and we
> still bail out with assert. Why?
Because we waited for the system to be idle, so we expect the timeline
to have been completely retired, which implies that
timline->last_request is now NULL.
-Chris
_______________________________________________
Intel-gfx mailing list
Intel-gfx@xxxxxxxxxxxxxxxxxxxxx
https://lists.freedesktop.org/mailman/listinfo/intel-gfx
