[Intel-gfx] [PATCH 5/7] drm/i915: Reset semaphore page for gen8

[Joonas Lahtinen]

On ke, 2016-04-06 at 11:10 +0100, Chris Wilson wrote:
> On Wed, Apr 06, 2016 at 12:58:43PM +0300, Joonas Lahtinen wrote:
> > 
> > On ke, 2016-04-06 at 00:57 +0100, Chris Wilson wrote:
> > > 
> > > An oversight is that when we wrap the seqno, we need to reset the hw
> > > semaphore counters to 0. We did this for gen6 and gen7 and forgot to do
> > > so for the new implementation required for gen8 (legacy).
> > > 
> > > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
> > > Cc: Mika Kuoppala <mika.kuoppala at linux.intel.com>
> > > Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > > ---
> > >  drivers/gpu/drm/i915/intel_ringbuffer.c | 8 ++++++++
> > >  1 file changed, 8 insertions(+)
> > > 
> > > diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c
> > > index fb304df8085d..c7023d6ca0b7 100644
> > > --- a/drivers/gpu/drm/i915/intel_ringbuffer.c
> > > +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c
> > > @@ -2564,6 +2564,14 @@ void intel_ring_init_seqno(struct intel_engine_cs *engine, u32 seqno)
> > >  	}
> > >  	memset(engine->semaphore.sync_seqno, 0,
> > >  	       sizeof(engine->semaphore.sync_seqno));
> > > +	if (dev_priv->semaphore_obj) {
> > > +		struct drm_i915_gem_object *obj = dev_priv->semaphore_obj;
> > > +		struct page *page = i915_gem_object_get_dirty_page(obj, 0);
> > > +		uint64_t *semaphores = kmap(page);
> > > +		memset(semaphores + engine->id * I915_NUM_ENGINES, 0,
> > > +		       sizeof(*semaphores) * I915_NUM_ENGINES);
> > There is i915_semaphore_seqno_size define which the GEN8_WAIT_OFFSET
> > and GEN8_SIGNAL_OFFSET use. So rather use that to stay consistent.
> I didn't want the size, I wanted the type. What I really wanted were
> sensible macros...

The macros could use some cleanup is what I meant.

> 
> I can change this to i915_semaphore_seqno_size (even though that is not
> the right name) and void *.
>  
> > 
> > Other than that,
> > 
> > Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> > 
> > PS. The existing semaphore code could use some cleanup, adding to
> > backlog.
> The existing semaphore code is 3 patches from working...
> 1. fix hw-id
> 2. fix signaling
> 3. reset pd after wait
> 4. enable/profit
> -Chris
> 
-- 
Joonas Lahtinen
Open Source Technology Center
Intel Corporation