[Bug 73037] [BYT]igt/many kms_flip subcases randomly fail with *ERROR* failed to train DP, aborting

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=73037

--- Comment #22 from Todd Previte <tprevite at gmail.com> ---
So this:
[   94.380058] [drm:_edp_panel_vdd_on] PP_STATUS: 0x00000000 PP_CONTROL:
0xabcd0008
[   94.380061] [drm:_edp_panel_vdd_on] eDP was not running
[   94.584341] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.588878] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.592886] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.596936] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.599478] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.613493] [drm:intel_dp_set_signal_levels] Using signal levels 00000000
[   94.616148] [drm:intel_dp_aux_ch] dp_aux_ch timeout status 0x71450064
[   94.616157] [drm:intel_dp_start_link_train] *ERROR* failed to enable link
training

shows that we're trying to train the link when the sink isn't ready. The
timeout status for the AUX transactions is expected in this case. Further down
in the log is this:

[   94.904063] [drm:intel_dp_set_signal_levels] Using signal levels 00000000
[   94.904882] ------------[ cut here ]------------
[   94.904914] WARNING: CPU: 0 PID: 4020 at
drivers/gpu/drm/i915/intel_dp.c:3170 intel_dp_complete_link_train+0x100/0x27f
[i915]()

caused by calling intel_dp_complete_link_train() when DP has not been enabled
in the first place. Which makes sense considering the previous failure to begin
link training. I believe the root cause of this is that we're continuing the
training process even though previous, required steps have failed. I think I
can clean this up with a little bit of rework to the link training functions
and how they're called.

-- 
You are receiving this mail because:
You are the QA Contact for the bug.
You are on the CC list for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20140702/4701dccd/attachment.html>