igt@gem_exec_balancer@bonded-slice - incomplete - system hang

https://intel-gfx-ci.01.org/tree/drm-tip/CI_DRM_7498/shard-tglb6/igt@gem_exec_balancer@bonded-slice.html

<6> [707.158178] Console: switching to colour dummy device 80x25
<6> [707.158217] [IGT] gem_exec_balancer: executing
<5> [707.162185] Setting dangerous option reset - tainting kernel
<6> [707.165179] [IGT] gem_exec_balancer: starting subtest bonded-slice
<7> [710.129404] [drm:edp_panel_vdd_off_sync [i915]] Turning [ENCODER:275:DDI A] VDD off
<7> [710.129632] [drm:edp_panel_vdd_off_sync [i915]] PP_STATUS: 0x80000008 PP_CONTROL: 0x00000067
<7> [710.129666] [drm:intel_power_well_disable [i915]] disabling DC off
<7> [710.129705] [drm:skl_enable_dc6 [i915]] Enabling DC6
<7> [710.129739] [drm:gen9_set_dc_state [i915]] Setting DC state from 00 to 02
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