Created attachment 123868 [details] dmesg with intel-drm-nightly My Skylake Lenovo L460 hard freezes randomly if multiple monitors are connected. With 4.6 mainline it is not as bad as with intel-drm-nightly. When using only the integrated display (eDP1) everything runs smoothly without lockup issues. The monitors I have connected right now are conntected to the Ultra Dock (DVI+HDMI), which comes with a Synaptics VMM2322 DP switch (FW: 2.30.000). CPU: i5-6200U Kernel: 4.6 with intel-drm-nightly BIOS: 1.14 xf86-video-intel: 1:2.99.917+645+g88733a7-1 libdrm: 2.4.68-1 xorg-server: 1.18.3-1 Arch Linux Ever since the watermark issues have been fixed (#89055) I am also getting FIFO underruns: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun I don't know if this could be related to the lockups. Unfortunately I cannot get a crash dump, as the entire machine locks up hard. Prior to the lockup `drm/card0/error` is empty.
Created attachment 123869 [details] regdump
Created attachment 123870 [details] xrandr --verbose
Created attachment 123871 [details] VBIOS Dump from Bios 1.13 This VBIOS dump is from 1.13. Starting with 1.14 I cannot dump the VBIOS any more, as I am getting the following message: i915 0000:00:02.0: Invalid PCI ROM header signature: expecting 0xaa55, got 0xffff
I spoke too soon in comment #c0 - I am also getting the "CPU pipe A FIFO underrun" on 4.6 stable (when in Ultra Dock). Lockup-wise there is one big difference between 4.6 stable and intel-drm-nightly: On 4.6 I am only getting random lockups on shutdown/reboot (suspend works, though). This means I can work sort of normally on 4.6 stable. On intel-drm-nightly I am getting these lockups within an X session, after some (between 5 and 90?) minutes of normal work. I'd like to help nailing this down further, but unfortunately hard lockup means there is no stacktrace and zero interaction possibility for me (CAPS lock LED on external keyboard is also dead). I also could not get SysRq to work to at least display something useful. Any advice on how I could provide more useful information is also appreciated.
I haven't experienced any hard freezes for a couple of weeks now, so I am closing this bug.
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