[Intel-gfx] [PATCH 1/3] drm/i915: Use intel_engine_stop_cs when stopping ringbuffer

[Chris Wilson]

Quoting Mika Kuoppala (2019-02-27 17:03:38)
> Mika Kuoppala <mika.kuoppala at linux.intel.com> writes:
> 
> > We have an exported function for stopping the engine before
> > disabling a ringbuffer. Take it into use.
> >
> > Cc: Chris Wilson <chris at chris-wilson.co.uk>
> > Signed-off-by: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> > ---
> >  drivers/gpu/drm/i915/intel_engine_cs.c  |  3 +++
> >  drivers/gpu/drm/i915/intel_ringbuffer.c | 31 +++++++++++--------------
> >  2 files changed, 16 insertions(+), 18 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
> > index 4f244019560d..3feb0f74c239 100644
> > --- a/drivers/gpu/drm/i915/intel_engine_cs.c
> > +++ b/drivers/gpu/drm/i915/intel_engine_cs.c
> > @@ -817,6 +817,9 @@ void intel_engine_cancel_stop_cs(struct intel_engine_cs *engine)
> >  {
> >       struct drm_i915_private *dev_priv = engine->i915;
> >  
> > +     if (INTEL_GEN(dev_priv) < 3)
> > +             return;
> > +
> >       GEM_TRACE("%s\n", engine->name);
> >  
> >       I915_WRITE_FW(RING_MI_MODE(engine->mmio_base),
> > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> > index 1b96b0960adc..5363dad1208d 100644
> > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> > @@ -607,23 +607,19 @@ static void ring_setup_status_page(struct intel_engine_cs *engine)
> >  static bool stop_ring(struct intel_engine_cs *engine)
> >  {
> >       struct drm_i915_private *dev_priv = engine->i915;
> > +     int ret;
> >  
> > -     if (INTEL_GEN(dev_priv) > 2) {
> > -             I915_WRITE_MODE(engine, _MASKED_BIT_ENABLE(STOP_RING));
> > -             if (intel_wait_for_register(dev_priv,
> > -                                         RING_MI_MODE(engine->mmio_base),
> > -                                         MODE_IDLE,
> > -                                         MODE_IDLE,
> > -                                         1000)) {
> > -                     DRM_ERROR("%s : timed out trying to stop ring\n",
> > -                               engine->name);
> > -                     /* Sometimes we observe that the idle flag is not
> > -                      * set even though the ring is empty. So double
> > -                      * check before giving up.
> > -                      */
> > -                     if (I915_READ_HEAD(engine) != I915_READ_TAIL(engine))
> > -                             return false;
> > -             }
> > +     ret = intel_engine_stop_cs(engine);
> > +     if (ret == -ENODEV)
> > +             ret = 0;
> > +
> > +     if (ret) {
> > +             /* Sometimes we observe that the idle flag is not
> > +              * set even though the ring is empty. So double
> > +              * check before giving up.
> > +              */
> > +             if (I915_READ_HEAD(engine) != I915_READ_TAIL(engine))
> 
> Hmm these could have been also converted to the _FW variants.

Sneak it in.
-Chris