Faced with sporadic machine hangs on gen7, that mimic the issue of concurrent writes to the same cacheline and seem to start with commit 9b9ed309 (drm/i915: Remove forcewake dance from seqno/irq barrier on legacy gen6+), let us restore the spinlock around the mmio read. Fixes: 9b9ed3093613288247a27a55a6dd07f1222150f1 Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx> Cc: Mika Kuoppala <mika.kuoppala@xxxxxxxxx> --- drivers/gpu/drm/i915/intel_ringbuffer.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_ringbuffer.c b/drivers/gpu/drm/i915/intel_ringbuffer.c index 66f69cdd1d36..ad5bd3808d8b 100644 --- a/drivers/gpu/drm/i915/intel_ringbuffer.c +++ b/drivers/gpu/drm/i915/intel_ringbuffer.c @@ -1590,7 +1590,10 @@ gen6_seqno_barrier(struct intel_engine_cs *engine) * interrupt (with the same net latency). */ struct drm_i915_private *dev_priv = engine->dev->dev_private; + + spin_lock_irq(&dev_priv->uncore.lock); POSTING_READ_FW(RING_ACTHD(engine->mmio_base)); + spin_unlock_irq(&dev_priv->uncore.lock); } static u32 -- 2.8.1 _______________________________________________ Intel-gfx mailing list Intel-gfx@xxxxxxxxxxxxxxxxxxxxx https://lists.freedesktop.org/mailman/listinfo/intel-gfx
