[Bug 92878] eDP link clock recovery fails with *ERROR* too many full retries, give up

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=92878

Peter Wu <peter at lekensteyn.nl> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |peter at lekensteyn.nl

--- Comment #18 from Peter Wu <peter at lekensteyn.nl> ---
Created attachment 124247
  --> https://bugs.freedesktop.org/attachment.cgi?id=124247&action=edit
dmesg for v4.7-rc1 (Clevo P651RA, annotated with commands and drm.debug=0xe)

Sometimes (with kernels from 4.5.x, 4.6, 4.7-rc1) when my eDP screen goes into
sleep, the scren stays black while the backlight is on. DP link training errors
show up in dmesg. This happens on both a Clevo P651RA and P671RA (similar
models except for the screen size), both with a resolution of 1920x1080.

According to the P671RA user, switching between a text console and the
graphical console sometimes works (works too for me). For my P651RA, so far
(2x) these commands also revives the screen:

cd /sys/class/drm/card0-eDP-1
echo off > status; sleep .1; echo detect > status

For testing purposes, you can use this instead of waiting for the sleep:
xset dpms force suspend

I can fully reproduce the issue with:
while :; do
    xset dpms force suspend;
    read -p WAIT -s;
    echo REVIVE;
    echo > /sys/class/drm/card0-eDP-1/status off;
    sleep .1;
    echo > /sys/class/drm/card0-eDP-1/status detect;
    echo DONE;
    read -p NEXT -s;
done

When "WAIT" is displayed, press a key. Screen will be black. Press Enter and
notice "REVIVE" followed by "DONE". Then the screen will be back. Finally press
Enter at "NEXT" to repeat the test. This was tested on v4.7-rc1 + unrelated
PCI/PM and nouveau patches on Arch Linux (Xorg 1.18.3, xf86-video-intel
1:2.99.917+645+g88733a7-1).


Jeronimo, if your "function key" issues are related to brightness adjustment,
can you try these patches:
https://lists.freedesktop.org/archives/intel-gfx/2016-March/090593.html
https://lists.freedesktop.org/archives/intel-gfx/2016-May/096910.html

otherwise please submit your machine to https://bugs.launchpad.net/bugs/752542

-- 
You are receiving this mail because:
You are on the CC list for the bug.
You are the QA Contact for the bug.
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20160601/3d046a34/attachment.html>