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authorChris Wilson <chris@chris-wilson.co.uk>2017-05-30 13:13:34 +0100
committerChris Wilson <chris@chris-wilson.co.uk>2017-06-01 14:22:16 +0100
commitaed2fc102ffaa9bd41e4cff140d3ec8482d13ff5 (patch)
tree715b9530c51a80dce3c535a10b8328c26c23ec64 /drivers/gpu/drm/i915/intel_engine_cs.c
parent04f7b24eccdfae680a36e9825fe0d61dcd5ed528 (diff)
downloadop-kernel-dev-aed2fc102ffaa9bd41e4cff140d3ec8482d13ff5.zip
op-kernel-dev-aed2fc102ffaa9bd41e4cff140d3ec8482d13ff5.tar.gz
drm/i915: Check the ring is empty when declaring the engines are idle
As another precaution when testing whether the CS engine is actually idle, also inspect the ring's HEAD/TAIL registers, which should be equal when there are no commands left to execute by the GPU. Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk> Cc: Mika Kuoppala <mika.kuoppala@intel.com> Link: http://patchwork.freedesktop.org/patch/msgid/20170530121334.17364-3-chris@chris-wilson.co.uk Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Diffstat (limited to 'drivers/gpu/drm/i915/intel_engine_cs.c')
-rw-r--r--drivers/gpu/drm/i915/intel_engine_cs.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/drivers/gpu/drm/i915/intel_engine_cs.c b/drivers/gpu/drm/i915/intel_engine_cs.c
index 699f2d3..bc38bd1 100644
--- a/drivers/gpu/drm/i915/intel_engine_cs.c
+++ b/drivers/gpu/drm/i915/intel_engine_cs.c
@@ -1212,6 +1212,11 @@ static bool ring_is_idle(struct intel_engine_cs *engine)
intel_runtime_pm_get(dev_priv);
+ /* First check that no commands are left in the ring */
+ if ((I915_READ_HEAD(engine) & HEAD_ADDR) !=
+ (I915_READ_TAIL(engine) & TAIL_ADDR))
+ idle = false;
+
/* No bit for gen2, so assume the CS parser is idle */
if (INTEL_GEN(dev_priv) > 2 && !(I915_READ_MODE(engine) & MODE_IDLE))
idle = false;
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