[Bug 97985] New: [BDW] System hang while running Qt QML application, with unclaimed registers

[bugzilla-daemon at freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=97985

            Bug ID: 97985
           Summary: [BDW] System hang while running Qt QML application,
                    with unclaimed registers
           Product: DRI
           Version: DRI git
          Hardware: x86-64 (AMD64)
                OS: Linux (All)
            Status: NEW
          Severity: normal
          Priority: medium
         Component: DRM/Intel
          Assignee: intel-gfx-bugs at lists.freedesktop.org
          Reporter: anssi.hannula at bitwise.fi
        QA Contact: intel-gfx-bugs at lists.freedesktop.org
                CC: intel-gfx-bugs at lists.freedesktop.org
     i915 platform: BDW

Created attachment 126897
  --> https://bugs.freedesktop.org/attachment.cgi?id=126897&action=edit
BDW hang with intel-drm-nightly 20160927

The system hangs whenever a Qt QML application has run for a while (minutes or
hours). Qt QML uses OpenGL for rendering. It is a full system hang, not just
GPU.

E.g. simply running the "quickwidget" example application in Qt 5.6.1
(qtdeclarative/examples/quick/quickwidgets/quickwidget , with the rotating red
square) will trigger a full system freeze within a day (within minutes most of
the time).

When the application starts, within seconds (i.e. long before the freeze) there
is always an "Unclaimed register detected" warning in the log, one of these:
- Unclaimed register detected before writing to register 0x44324
- Unclaimed register detected before writing to register 0x220a8
- Unclaimed register detected before reading register 0x44408

This message is not there with e.g. glxgears (with which I have also not been
able to reproduce the hang so far).

With serial console I see no output at the time of freeze.

The issue happens also with latest intel processor microcode (loaded using the
early load mechanism).

With "intel_idle.max_cstate=1" kernel parameter the hang does not occur, or at
least it occurs so much more rarely that I haven't seen it.


The attached logs are all with drm-intel-nightly with drm.debug=0xe.

bdw-hang-nightly-20160927.txt contains a quickwidget hang captured via serial
port, and it also contains an unclaimed register warning for register 0x44324.

bdw-unclaimed-0x220a8.txt and bdw-unclaimed-0x44408.txt contain the other
variants of the "Unclaimed register" warning that I have seen, but I did not
wait for the freeze to actually happen in these instances (but I've seen the
hang happen with those messages in other runs with different kernel and without
drm debugging).



The setup is:

System architecture: x86_64

Kernel version: drm-intel-nightly 2016y-09m-27d-16h-32m-56s UTC (also seen in
4.4.18, 4.4.22, 4.8-rc8).

Linux distribution: Yocto 2.1-based build (mesa 11.1.1, X.org 1.18.0).

Machine model: Sintrones VBOX-3610

Display connector: DVI (appears as HDMI1)

-- 
You are receiving this mail because:
You are the assignee for the bug.
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: <https://lists.freedesktop.org/archives/intel-gfx-bugs/attachments/20160930/70becece/attachment.html>