From 74d00d28a15c8452f65de0a9477b52d95639cc63 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@chris-wilson.co.uk>
Date: Mon, 12 Feb 2018 09:39:28 +0000
Subject: [PATCH] drm/i915: Don't wake the device up to check if the engine is
asleep
If the entire device is powered off, we can safely assume that the
engine is also asleep (and idle).
Reported-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: a091d4ee931b ("drm/i915: Hold a wakeref for probing the ring registers")
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180212093928.6005-1-chris@chris-wilson.co.uk
---
drivers/gpu/drm/i915/intel_engine_cs.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 0ad9184eba978..3efc589a7f37f 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1464,7 +1464,9 @@ static bool ring_is_idle(struct intel_engine_cs *engine)
struct drm_i915_private *dev_priv = engine->i915;
bool idle = true;
- intel_runtime_pm_get(dev_priv);
+ /* If the whole device is asleep, the engine must be idle */
+ if (!intel_runtime_pm_get_if_in_use(dev_priv))
+ return true;
/* First check that no commands are left in the ring */
if ((I915_READ_HEAD(engine) & HEAD_ADDR) !=
--
2.30.2