drm/i915: Assert the local engine->wakeref is active

Due to the asynchronous tasklet and recursive GT wakeref, it may happen
that we submit to the engine (underneath it's own wakeref) prior to the
central wakeref being marked as taken. Switch to checking the local wakeref
for greater consistency.

Fixes: 79ffac8599c4 ("drm/i915: Invert the GEM wakeref hierarchy")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20190503115225.30831-3-chris@chris-wilson.co.uk

diff --git a/drivers/gpu/drm/i915/gt/intel_engine_cs.c b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
index 5907a96136413e7190b519f4176cf089c091e359..416d7e2e6f8ca76c31a63dd278a57a2e29e06c34 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/gt/intel_engine_cs.c
@@ -1090,6 +1090,9 @@ bool intel_engine_is_idle(struct intel_engine_cs *engine)
        if (i915_reset_failed(engine->i915))
                return true;
 
+       if (!intel_wakeref_active(&engine->wakeref))
+               return true;
+
        /* Waiting to drain ELSP? */
        if (READ_ONCE(engine->execlists.active)) {
                struct tasklet_struct *t = &engine->execlists.tasklet;

diff --git a/drivers/gpu/drm/i915/gt/intel_lrc.c b/drivers/gpu/drm/i915/gt/intel_lrc.c
index 7d69d07490e83b01fa7b194763aa58fe5276e820..5580b6f1aa0cba565964fff5840106af0251beda 100644 (file)
--- a/drivers/gpu/drm/i915/gt/intel_lrc.c
+++ b/drivers/gpu/drm/i915/gt/intel_lrc.c
@@ -535,7 +535,7 @@ static void execlists_submit_ports(struct intel_engine_cs *engine)
         * that all ELSP are drained i.e. we have processed the CSB,
         * before allowing ourselves to idle and calling intel_runtime_pm_put().
         */
-       GEM_BUG_ON(!engine->i915->gt.awake);
+       GEM_BUG_ON(!intel_wakeref_active(&engine->wakeref));
 
        /*
         * ELSQ note: the submit queue is not cleared after being submitted
@@ -1085,7 +1085,7 @@ static void execlists_submission_tasklet(unsigned long data)
 
        GEM_TRACE("%s awake?=%d, active=%x\n",
                  engine->name,
-                 !!engine->i915->gt.awake,
+                 !!intel_wakeref_active(&engine->wakeref),
                  engine->execlists.active);
 
        spin_lock_irqsave(&engine->timeline.lock, flags);