drm/i915: Separate out the seqno-barrier from engine->get_seqno
In order to simplify future patches, extract the
lazy_coherency optimisation our of the engine->get_seqno() vfunc into
its own callback.
v2: Rename the barrier to engine->irq_seqno_barrier to try and better
reflect that the barrier is only required after the user interrupt before
reading the seqno (to ensure that the seqno update lands in time as we
do not have strict seqno-irq ordering on all platforms).
Reviewed-by: Dave Gordon <david.s.gordon@intel.com> [#v2]
v3: Comments for hangcheck paranoia. Mika wanted to keep the extra
barrier inside the hangcheck, just in case. I can argue that it doesn't
provide a barrier against anything, but the side-effects of applying the
barrier may prevent a false declaration of a hung GPU.
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Cc: Dave Gordon <david.s.gordon@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460195877-20520-2-git-send-email-chris@chris-wilson.co.uk
diff --git a/drivers/gpu/drm/i915/i915_drv.h b/drivers/gpu/drm/i915/i915_drv.h
index a93e5dd..5424016 100644
--- a/drivers/gpu/drm/i915/i915_drv.h
+++ b/drivers/gpu/drm/i915/i915_drv.h
@@ -3017,15 +3017,19 @@
static inline bool i915_gem_request_started(struct drm_i915_gem_request *req,
bool lazy_coherency)
{
- u32 seqno = req->engine->get_seqno(req->engine, lazy_coherency);
- return i915_seqno_passed(seqno, req->previous_seqno);
+ if (!lazy_coherency && req->engine->irq_seqno_barrier)
+ req->engine->irq_seqno_barrier(req->engine);
+ return i915_seqno_passed(req->engine->get_seqno(req->engine),
+ req->previous_seqno);
}
static inline bool i915_gem_request_completed(struct drm_i915_gem_request *req,
bool lazy_coherency)
{
- u32 seqno = req->engine->get_seqno(req->engine, lazy_coherency);
- return i915_seqno_passed(seqno, req->seqno);
+ if (!lazy_coherency && req->engine->irq_seqno_barrier)
+ req->engine->irq_seqno_barrier(req->engine);
+ return i915_seqno_passed(req->engine->get_seqno(req->engine),
+ req->seqno);
}
int __must_check i915_gem_get_seqno(struct drm_device *dev, u32 *seqno);