From 4abb534e2217d00b314267472bf4ef5cfcf5d268 Mon Sep 17 00:00:00 2001 From: Mika Kuoppala Date: Mon, 30 Nov 2015 17:15:01 +0200 Subject: [PATCH 1/4] drm/i915: Teach hangcheck about long operations on rings Some operations that happen in ringbuffer, like flushing, can take significant amounts of time. After some intense shader tests, the PIPE_CONTROl with flush can apparently last longer time than what is our hangcheck tick (1500ms). If this happens twice in a row, even with subsequent batches, the hangcheck score decaying mechanism can't cope and hang is declared. Strip out actual head checking to a separate function and if actual head has not moved, check if it is lingering inside the ringbuffer as opposed to batch. If so, treat it as if it would be inside loop to only slightly increment the hangcheck score. References: https://bugs.freedesktop.org/show_bug.cgi?id=93029 Signed-off-by: Mika Kuoppala --- drivers/gpu/drm/i915/i915_irq.c | 28 ++++++++++++++++++++++++++-- 1 file changed, 26 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/i915/i915_irq.c b/drivers/gpu/drm/i915/i915_irq.c index e88d692..6ed6571 100644 --- a/drivers/gpu/drm/i915/i915_irq.c +++ b/drivers/gpu/drm/i915/i915_irq.c @@ -2914,11 +2914,11 @@ static void semaphore_clear_deadlocks(struct drm_i915_private *dev_priv) } static enum intel_ring_hangcheck_action -ring_stuck(struct intel_engine_cs *ring, u64 acthd) +head_stuck(struct intel_engine_cs *ring, u64 acthd) { struct drm_device *dev = ring->dev; struct drm_i915_private *dev_priv = dev->dev_private; - u32 tmp; + u32 head; if (acthd != ring->hangcheck.acthd) { if (acthd > ring->hangcheck.max_acthd) { @@ -2929,6 +2929,30 @@ ring_stuck(struct intel_engine_cs *ring, u64 acthd) return HANGCHECK_ACTIVE_LOOP; } + head = I915_READ_HEAD(ring) & HEAD_ADDR; + + /* Some operations, like pipe flush, can take a long time. + * Detect if we are inside ringbuffer and treat these as if + * the ring would be busy. + */ + if (lower_32_bits(acthd) == head) + return HANGCHECK_ACTIVE_LOOP; + + return HANGCHECK_HUNG; +} + +static enum intel_ring_hangcheck_action +ring_stuck(struct intel_engine_cs *ring, u64 acthd) +{ + struct drm_device *dev = ring->dev; + struct drm_i915_private *dev_priv = dev->dev_private; + enum intel_ring_hangcheck_action ha; + u32 tmp; + + ha = head_stuck(ring, acthd); + if (ha != HANGCHECK_HUNG) + return ha; + if (IS_GEN2(dev)) return HANGCHECK_HUNG; -- 2.5.0