Created attachment 108551 [details]
dmesg

==System Environment==
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Regression: not sure, it also has bug 68463
Test on drm-intel-next-queued/6e47e3f097cc6c4cb470a805a3fa07a8e8376dab, it also has this issue.

Non-working platforms: HSW

==kernel==
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drm-intel-nightly/32cefad9992e67b4ee7487adf465bd7e189c9c1c

==Bug detailed description==
Run this case, it causes system hang, It happens only one HSW machine.

output:
IGT-Version: 1.8-g15972aa (x86_64) (Linux: 3.18.0-rc2_drm-intel-nightly_32cefa_20141028+ x86_64)
Testing: clone-exclusive-crtc 2 connector combinations
  Test id#1 CRTC count 2
    CRTC[8] [Pipe A] Mode: 640x480@60Hz Connectors: VGA-1[18] (NC)

lspci:
00:00.0 Host bridge: Intel Corporation Haswell DRAM Controller (rev 06)
00:02.0 VGA compatible controller: Intel Corporation Haswell Integrated Graphics Controller (rev 06)
00:03.0 Audio device: Intel Corporation Haswell HD Audio Controller (rev 06)
00:14.0 USB controller: Intel Corporation Lynx Point USB xHCI Host Controller (rev 04)
00:16.0 Communication controller: Intel Corporation Lynx Point MEI Controller #1 (rev 04)
00:19.0 Ethernet controller: Intel Corporation Ethernet Connection I217-V (rev 04)
00:1a.0 USB controller: Intel Corporation Lynx Point USB Enhanced Host Controller #2 (rev 04)
00:1b.0 Audio device: Intel Corporation Lynx Point High Definition Audio Controller (rev 04)
00:1c.0 PCI bridge: Intel Corporation Lynx Point PCI Express Root Port #1 (rev d4)
00:1c.2 PCI bridge: Intel Corporation Lynx Point PCI Express Root Port #3 (rev d4)
00:1c.3 PCI bridge: Intel Corporation Lynx Point PCI Express Root Port #4 (rev d4)
00:1c.4 PCI bridge: Intel Corporation Lynx Point PCI Express Root Port #5 (rev d4)
00:1d.0 USB controller: Intel Corporation Lynx Point USB Enhanced Host Controller #1 (rev 04)
00:1f.0 ISA bridge: Intel Corporation Lynx Point LPC Controller (rev 04)
00:1f.2 SATA controller: Intel Corporation Lynx Point 6-port SATA Controller 1 [AHCI mode] (rev 04)
00:1f.3 SMBus: Intel Corporation Lynx Point SMBus Controller (rev 04)
01:00.0 SATA controller: ASMedia Technology Inc. ASM1062 Serial ATA Controller (rev 01)
02:00.0 PCI bridge: Integrated Technology Express, Inc. Device 8892 (rev 41)
03:02.0 FireWire (IEEE 1394): Texas Instruments TSB43AB22A IEEE-1394a-2000 Controller (PHY/Link) [iOHCI-Lynx]
04:00.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
05:07.0 PCI bridge: PLX Technology, Inc. PEX 8606 6 Lane, 6 Port PCI Express Gen 2 (5.0 GT/s) Switch (rev ba)
06:00.0 Ethernet controller: Intel Corporation I210 Gigabit Network Connection (rev 03)

==Reproduce steps==
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1. ./kms_setmode --run-subtest clone-exclusive-crtc