https://bugs.freedesktop.org/show_bug.cgi?id=110629

Bug ID: 110629 Summary: Intel i915 graphics driver issues with external monitor when laptop in docking station (opensuse bug 1132926) Product: Mesa Version: unspecified Hardware: x86-64 (AMD64) URL: https://bugzilla.opensuse.org/show_bug.cgi?id=1132926 OS: Linux (All) Status: NEW Keywords: regression Severity: normal Priority: medium Component: Drivers/DRI/i915 Assignee: dri-devel@lists.freedesktop.org Reporter: otrebor@swissonline.ch QA Contact: dri-devel@lists.freedesktop.org CC: tiwai@suse.de

I have a HP EliteBook 840 G2 running openSUSE Leap 15.0 with all patches applied. The laptop runs fine when it is in normal portable mode (off dock), also with an external monitor. When I dock it into its docking station at home, I experience weird graphic device behaviour. It is a matter of luck if it is able to initialize and configure the attached external monitor the way it is expected. Sometimes it hangs in an endless config loop when trying to initialize the monitor. The external monitor is a SAMSUNG U28D590D connected via display port to port #1 to the docking station. However, if I undock the laptop and plug the very same display cable to the onboard display port then the display and the laptop run as expected. It really is an issue I can only experience when putting the device into the docking station. For comparison: I had the chance to try another device, a HP EliteBook 840 G3 with the very same docking station and monitor. It was running Windows 7 and I did not see any strange behaviour. Additionally, I was earlier running openSUSE 42.3 on the very same device configuration and did not have any issues. The odd behaviour only started after upgrading to Leap 15.0 and got worse with each patch cycle, to reach total unusability as of today. Hence, thats why I am writing this bug report. One thing I occasionally see is this error message in the logs: kernel: [drm:intel_cpu_fifo_underrun_irq_handler [i915]] *ERROR* CPU pipe C FIFO underrun

I attaching output from dmesg, journalctl, and xrandr in different configurations. Let me know if you need more. Thanks for the support.

Please also refer to opensuse bug #1132926 here for more details: https://bugzilla.opensuse.org/show_bug.cgi?id=1132926

Somehow might relate to this bug here: https://bugs.freedesktop.org/show_bug.cgi?id=95298 However, my enviroenment refers to the Intel i915 graphics driver as I have no Radeon hardware.

Please also see the opensuse bug first. Let me know If you need more info. Thanks for the support.