Cfrtjryk

My system has problems with the displayport connection. This is indicated by several problems that, at the first glance, do not have anything in common. The reason why I claim DP for being the cause, is that when I connect another monitor via DVI these problems just vanish.

When I put monitor into sleep it won't wake up. Journal contains:

[drm:intel_dp_start_link_train] *ERROR* failed to enable link

and sometimes

[drm:i915_hangcheck_elapsed] *ERROR* Hangcheck timer elapsed... GPU hung

Qt applications need a few seconds to start. And meanwhile freeze X. Today I had a complete never-ending system freeze. As a followup KDE start is painfully slow and accompanied by multiple freezes.

I use an up-to-date Arch System on an i5-4590, using the Intel HD4600.

Here is dmesg with drm.debug=0xe comandline. I cut about a million "[drm:drm_dp_i2c_do_msg] native defer" lines to make it cleaner.

Intel drivers are installed. The config:

# for i in /sys/module/i915/parameters/*; do echo $i=$(cat $i); done

/sys/module/i915/parameters/disable_display=N

/sys/module/i915/parameters/disable_power_well=1

/sys/module/i915/parameters/enable_cmd_parser=0

/sys/module/i915/parameters/enable_fbc=-1

/sys/module/i915/parameters/enable_hangcheck=Y

/sys/module/i915/parameters/enable_ips=1

/sys/module/i915/parameters/enable_ppgtt=1

/sys/module/i915/parameters/enable_psr=0

/sys/module/i915/parameters/enable_rc6=-1

/sys/module/i915/parameters/fastboot=N

/sys/module/i915/parameters/invert_brightness=0

/sys/module/i915/parameters/lvds_channel_mode=0

/sys/module/i915/parameters/lvds_downclock=0

/sys/module/i915/parameters/lvds_use_ssc=-1

/sys/module/i915/parameters/modeset=-1

/sys/module/i915/parameters/panel_ignore_lid=1

/sys/module/i915/parameters/powersave=1

/sys/module/i915/parameters/prefault_disable=N

/sys/module/i915/parameters/preliminary_hw_support=0

/sys/module/i915/parameters/reset=Y

/sys/module/i915/parameters/semaphores=-1

/sys/module/i915/parameters/vbt_sdvo_panel_type=-1

I've had the exact same issues and setting

/sys/module/i915/parameters/semaphores 

to 1 solved it for me. Have you tried this?