[Bug 107546] Screen is frozen on second connection of DP MST dock

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=107546

--- Comment #36 from Vedran Furač <1vf+freedesktop at posteo.net> ---
Hello,

An update, seems that even with 4.10 it doesn't work perfectly on NUC. After
switching input back to DP input for the 3rd or 4th time, nothing happened,
display showed "no signal" error. However, X remained fully functional and
after disconnecting the cable and reconnecting it, both displays were detected
and worked fine afterwards.


I have similar problem on Thinkpad X1 carbon 5th gen (4.18 kernel). Initially
it works fine, but upon disconnecting displays (TB/DP) there's this error:

[30373.030578] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to enable
link training
[30373.298845] [drm:intel_encoders_pre_enable.isra.103 [i915]] *ERROR* failed
to allocate vcpi

and after connecting them again:

[33022.853059] [drm:intel_dp_start_link_train [i915]] *ERROR* Timed out waiting
for DP idle patterns
[33022.861393] [drm:intel_ddi_prepare_link_retrain [i915]] *ERROR* Timeout
waiting for DDI BUF C idle bit
...
[33057.741347] [drm:intel_dp_start_link_train [i915]] *ERROR* failed to get
link status

and obviously no signal on displays. Luckily there is no locking on Thinkpad
like on NUC and X still works fine, but I have to reboot to get external
displays working again.

I'll try to get debug output from Thinkpad tomorrow.

Regards,
Vedran

-- 
You are receiving this mail because:
You are on the CC list for the bug.
You are the QA Contact for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20181114/284b64ed/attachment-0001.html>