Bug 95498 - T460s (Skylake): System freeze when attaching a monitor to a Ultra Dock DP connector
Summary: T460s (Skylake): System freeze when attaching a monitor to a Ultra Dock DP co...
Status: CLOSED FIXED
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Intel (show other bugs)
Version: DRI git
Hardware: Other All
: medium normal
Assignee: Lyude Paul
QA Contact: Intel GFX Bugs mailing list
URL:
Whiteboard:
Keywords:
Depends on:
Blocks:
 
Reported: 2016-05-19 21:00 UTC by kaon
Modified: 2017-07-24 22:41 UTC (History)
3 users (show)

See Also:
i915 platform: SKL
i915 features: display/DP


Attachments
dmes (674.06 KB, text/plain)
2016-05-19 21:00 UTC, kaon
no flags Details
dmesg since boot (before the crash, debug=0x1e) (2.02 MB, text/plain)
2016-05-19 21:48 UTC, kaon
no flags Details

Description kaon 2016-05-19 21:00:26 UTC
Created attachment 123925 [details]
dmes

Kernel version: drm-intel-nightly @ c6740c9c9e914742fd2ec159142c40701f7df966 (2016-05-18)

Everything else is a stock Fedora 24 install running stock GNOME.

Devices involved:

  - Thinkpad T460s (i5-6200U)
  - Thinkpad Ultra Dock (latest firmware)
  - LG 27MU67-B (3840x2160, DP1.2)

Whenever I connect a monitor to the DP connector on the dock, the system freezes. I captured the last kmsgs before the freeze using netconsole, see attachment (drm.debug=0x1e).

A similar issue (probably the same) occurred when I attached a Dell full HD screen to the DVI port next to the DP connector (they somehow belong together according to the marking on the dock). System would freeze a few seconds after attaching the monitor, but the screen would sometimes work before the crash. No logs though for that, can acquire them if necessary.

Works fine with stock Windows 10 (full resolution, 60hz).

Problem seems to affect other users too:

  - https://www.reddit.com/r/thinkpad/comments/4c6fea/my_t460s_after_two_weeks_a_heavily_biased/ ("The display connectors are currently unusable with Linux and crash the kernel. This might be addressed with updated Intel drivers, I'm to lazy to fiddle around with it - so my external monitor runs with an adapter on the Mini-DP port, which fills up the desk. (Windows handles the connectors without problems.)")

  - https://bbs.archlinux.org/viewtopic.php?id=210229

Any help would be greatly appreciated. I have a working kernel development setup here and will do whatever is necessary to help with debugging.
Comment 1 kaon 2016-05-19 21:08:13 UTC
xrandr --verbose for the monitor from a Haswell system, which has no issues at all:

DP2-1 connected primary 3840x2160+2880+0 (0x123) normal (normal left inverted right x axis y axis) 600mm x 340mm
	Identifier: 0x120
	Timestamp:  228436444
	Subpixel:   unknown
	Gamma:      1.0:1.9:4.5
	Brightness: 1.0
	Clones:     DP2-2 DP2-3
	CRTC:       0
	CRTCs:      1 0 2
	Transform:  1.000000 0.000000 0.000000
	            0.000000 1.000000 0.000000
	            0.000000 0.000000 1.000000
	           filter: 
	EDID: 
		00ffffffffffff001e6d095b58650300
		0b190104b53c22789e3035a7554ea326
		0f50542108007140818081c0a9c0d1c0
		81000101010150d000a0f0703e800890
		650c58542100001a286800a0f0703e80
		0890650c58542100001a000000fd0038
		3d1e8738000a202020202020000000fc
		004c4720556c7472612048440a20018c
		02031171449004030123090707830100
		00023a801871382d40582c4500585421
		00001e00000000000000000000000000
		00000000000000000000000000000000
		00000000000000000000000000000000
		00000000000000000000000000000000
		00000000000000000000000000000000
		00000000000000000000000000000041
	Broadcast RGB: Automatic 
		supported: Automatic, Full, Limited 16:235
	audio: auto 
		supported: force-dvi, off, auto, on
  3840x2160 (0x123) 533.280MHz +HSync -VSync *current +preferred
        h: width  3840 start 3848 end 3992 total 4000 skew    0 clock 133.32KHz
        v: height 2160 start 2214 end 2219 total 2222           clock  60.00Hz
  3840x2160 (0x124) 266.640MHz +HSync -VSync
        h: width  3840 start 3848 end 3992 total 4000 skew    0 clock  66.66KHz
        v: height 2160 start 2214 end 2219 total 2222           clock  30.00Hz
  1920x1080 (0x125) 148.500MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.50KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  60.00Hz
  1920x1080 (0x126) 148.352MHz +HSync +VSync
        h: width  1920 start 2008 end 2052 total 2200 skew    0 clock  67.43KHz
        v: height 1080 start 1084 end 1089 total 1125           clock  59.94Hz
  1600x900 (0x127) 108.000MHz +HSync +VSync
        h: width  1600 start 1624 end 1704 total 1800 skew    0 clock  60.00KHz
        v: height  900 start  901 end  904 total 1000           clock  60.00Hz
  1280x1024 (0xf3) 108.000MHz +HSync +VSync
        h: width  1280 start 1328 end 1440 total 1688 skew    0 clock  63.98KHz
        v: height 1024 start 1025 end 1028 total 1066           clock  60.02Hz
  1280x800 (0x128) 83.500MHz -HSync +VSync
        h: width  1280 start 1352 end 1480 total 1680 skew    0 clock  49.70KHz
        v: height  800 start  803 end  809 total  831           clock  59.81Hz
  1152x864 (0x129) 81.579MHz -HSync +VSync
        h: width  1152 start 1216 end 1336 total 1520 skew    0 clock  53.67KHz
        v: height  864 start  865 end  868 total  895           clock  59.97Hz
  1280x720 (0x12a) 74.250MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  45.00KHz
        v: height  720 start  725 end  730 total  750           clock  60.00Hz
  1280x720 (0x12b) 74.176MHz +HSync +VSync
        h: width  1280 start 1390 end 1430 total 1650 skew    0 clock  44.96KHz
        v: height  720 start  725 end  730 total  750           clock  59.94Hz
  1024x768 (0xf8) 65.000MHz -HSync -VSync
        h: width  1024 start 1048 end 1184 total 1344 skew    0 clock  48.36KHz
        v: height  768 start  771 end  777 total  806           clock  60.00Hz
  800x600 (0xfb) 40.000MHz +HSync +VSync
        h: width   800 start  840 end  968 total 1056 skew    0 clock  37.88KHz
        v: height  600 start  601 end  605 total  628           clock  60.32Hz
  720x480 (0x12c) 27.027MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.50KHz
        v: height  480 start  489 end  495 total  525           clock  60.00Hz
  720x480 (0x12d) 27.000MHz -HSync -VSync
        h: width   720 start  736 end  798 total  858 skew    0 clock  31.47KHz
        v: height  480 start  489 end  495 total  525           clock  59.94Hz
  640x480 (0x12e) 25.200MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.50KHz
        v: height  480 start  490 end  492 total  525           clock  60.00Hz
  640x480 (0xfe) 25.175MHz -HSync -VSync
        h: width   640 start  656 end  752 total  800 skew    0 clock  31.47KHz
        v: height  480 start  490 end  492 total  525           clock  59.94Hz
Comment 2 kaon 2016-05-19 21:29:42 UTC
lspci -vvv:

00:02.0 VGA compatible controller: Intel Corporation HD Graphics 520 (rev 07) (prog-if 00 [VGA controller])
	Subsystem: Lenovo Device 2233
	Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
	Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
	Latency: 0
	Interrupt: pin A routed to IRQ 133
	Region 0: Memory at f0000000 (64-bit, non-prefetchable) [size=16M]
	Region 2: Memory at e0000000 (64-bit, prefetchable) [size=256M]
	Region 4: I/O ports at e000 [size=64]
	[virtual] Expansion ROM at 000c0000 [disabled] [size=128K]
	Capabilities: <access denied>
	Kernel driver in use: i915
	Kernel modules: i915
Comment 3 kaon 2016-05-19 21:48:17 UTC
Created attachment 123930 [details]
dmesg since boot (before the crash, debug=0x1e)
Comment 4 kaon 2016-05-21 18:43:50 UTC
I tried to attach the monitor directly using a DisplayPort cable and it did not freeze the system. The screen was correctly recognized and xrandr showed 4k at 60hz resolution, but it stayed black.

After switching to 30hz, the system crashed. Disabling DP1.2 on the monitor worked, but resulted in a grainy picture.

The cable is OK (I verified with another computer).
Comment 5 kaon 2016-05-25 20:17:56 UTC
Could not reproduce the issue with the FHD screens - it probably got fixed in 4.6.

Issue is perfectly reproducible with DP1.2/4k screen.
Comment 6 ComBin 2016-05-27 12:32:00 UTC
For me, reproduced on Dell Latitude E7470 (Intel HD Graphics 520) with core 4.4. System is stuck if i attach DP or enable a display in GUI.

Really fixed in 4.6.
Comment 7 kaon 2016-05-29 09:46:39 UTC
That's a different issue then. I've been using the full HD screens for a few days no and no more issues.

The 4k/DP1.2 monitor still crashes the system though so that's still unfixed.
Comment 8 Lyude Paul 2016-06-07 13:59:38 UTC
Over IRC this user informed me that this issue has been fixed with the latest nightly. Closing


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