drm/i915: Simplify check for idleness in hangcheck

Having fixed the tracking of the engine's last_submitted_seqno, we can
now rely on it for detecting when the engine is idle (and not have to
touch the requests pointer).

Testcase: igt/gem_exec_whisper
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1460010558-10705-9-git-send-email-chris@chris-wilson.co.uk
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>

diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c
index cc90812..c30a12e 100644 (file)
--- a/drivers/gpu/drm/i915/i915_irq.c
+++ b/drivers/gpu/drm/i915/i915_irq.c
@@ -2805,9 +2805,8 @@ static void gen8_disable_vblank(struct drm_device *dev, unsigned int pipe)
 static bool
 ring_idle(struct intel_engine_cs *engine, u32 seqno)
 {
-       return (list_empty(&engine->request_list) ||
-               i915_seqno_passed(seqno,
-                                 READ_ONCE(engine->last_submitted_seqno)));
+       return i915_seqno_passed(seqno,
+                                READ_ONCE(engine->last_submitted_seqno));
 }
 
 static bool