[Intel-gfx] [PATCH v2 2/2] drm/i915: Add assert for no pending GPU requests during suspend/resume in LR mode

[Imre Deak]

During resume we will reset the SW/HW tracking for each ring head/tail
pointers and so are not prepared to replay any pending requests (as
opposed to GPU reset time). Add an assert for this both to the suspend
and the resume code.

v2:
- Check for ELSP port idle already during suspend and check !gt.awake
  during resume. (Chris)

Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala at intel.com>
Signed-off-by: Imre Deak <imre.deak at intel.com>
---
 drivers/gpu/drm/i915/i915_gem.c  | 1 +
 drivers/gpu/drm/i915/intel_lrc.c | 2 ++
 2 files changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/i915_gem.c b/drivers/gpu/drm/i915/i915_gem.c
index 81ea88c..acc2030 100644
--- a/drivers/gpu/drm/i915/i915_gem.c
+++ b/drivers/gpu/drm/i915/i915_gem.c
@@ -4437,6 +4437,7 @@ int i915_gem_suspend(struct drm_device *dev)
 	 * reset the GPU back to its idle, low power state.
 	 */
 	WARN_ON(dev_priv->gt.awake);
+	WARN_ON(i915.enable_execlists && !intel_lr_engines_idle(dev_priv));
 
 	/*
 	 * Neither the BIOS, ourselves or any other kernel
diff --git a/drivers/gpu/drm/i915/intel_lrc.c b/drivers/gpu/drm/i915/intel_lrc.c
index 7aa5665..77577d1 100644
--- a/drivers/gpu/drm/i915/intel_lrc.c
+++ b/drivers/gpu/drm/i915/intel_lrc.c
@@ -2165,6 +2165,8 @@ void intel_lr_context_resume(struct drm_i915_private *dev_priv)
 			if (WARN_ON(IS_ERR(reg)))
 				continue;
 
+			WARN_ON(dev_priv->gt.awake);
+
 			reg += LRC_STATE_PN * PAGE_SIZE / sizeof(*reg);
 			reg[CTX_RING_HEAD+1] = 0;
 			reg[CTX_RING_TAIL+1] = 0;
-- 
2.5.0