Bug 108514 - heavy screen flickering with Mobility Radeon X1600 and kernel version onwards 3.13
Summary: heavy screen flickering with Mobility Radeon X1600 and kernel version onwards...
Status: NEW
Alias: None
Product: DRI
Classification: Unclassified
Component: DRM/Radeon (show other bugs)
Version: unspecified
Hardware: x86-64 (AMD64) Linux (All)
: medium normal
Assignee: Default DRI bug account
QA Contact:
URL:
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Keywords:
Depends on:
Blocks:
 
Reported: 2018-10-22 16:07 UTC by Werner Lueckel
Modified: 2018-12-07 16:40 UTC (History)
0 users

See Also:
i915 platform:
i915 features:


Attachments
dmesg Ubuntu14.04, Kernel3.13.0-160, radeon 2.36.0, screen O.K. (67.55 KB, text/plain)
2018-10-23 16:31 UTC, Werner Lueckel
no flags Details
dmesg Ubuntu18.04, Kernel4.15.0-36, radeon 2.50.0, screen flickering (62.17 KB, text/plain)
2018-10-23 16:34 UTC, Werner Lueckel
no flags Details
dmesg Ubuntu14.04, Kernel4.4.0-133, radeon 2.43.0, screen flickering (66.92 KB, text/plain)
2018-10-23 17:07 UTC, Werner Lueckel
no flags Details

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Description Werner Lueckel 2018-10-22 16:07:16 UTC
my laptop: HP Compaq nx9420
my grafic card:
01:00.0 VGA compatible controller: Advanced Micro Devices, Inc. [AMD/ATI] RV530/M56-P [Mobility Radeon X1600] (prog-if 00 [VGA controller])
screen resolution: 1680x1050@60.1

when booting UBUNTU "14.04.5 LTS, Trusty Tahr" kernel 3.13.0-160-generic
-> the screen is fine in text-mode and in grafic-mode; NO flickering.
boot-messages say:
[drm] Initialized radeon 2.36.0 ...

BUT,
when booting UBUNTU "18.04.1 LTS (Bionic Beaver)" kernel 4.15.0-36-generic
-> the screen starts heavy flickering as soon as the kernel-module "radeon.ko"
is loaded. The flickering continues in grafic-mode.
here the boot-messages say:
[drm] Initialized radeon 2.50.0 ...
so: this seems to be a new version of radeon.ko.

My question:
- is there a method or a 'hidden flag' to switch radeon.ko-2.50 back to the
  good behaviour of radeon.ko-2.16?
Comment 1 Alex Deucher 2018-10-22 18:14:39 UTC
Any chance you can narrow down when the regression occurred and bisect it using git?  Please attach your dmesg output and xorg log (if using X).
Comment 2 Werner Lueckel 2018-10-23 16:31:25 UTC
Created attachment 142154 [details]
dmesg Ubuntu14.04, Kernel3.13.0-160, radeon 2.36.0, screen O.K.
Comment 3 Werner Lueckel 2018-10-23 16:34:59 UTC
Created attachment 142155 [details]
dmesg Ubuntu18.04, Kernel4.15.0-36, radeon 2.50.0, screen flickering
Comment 4 Werner Lueckel 2018-10-23 16:45:12 UTC
- I attached 2 dmesg-listings;
  booting Ubuntu14.04, Kernel3.13 -> screen is o.k.; no flickering
  booting Ubuntu18.04, Kernel4.15 -> screen flickers.
- no Xorg log since the flickering happens already in text-mode
- I did the following test (on Ubuntu18.04):
  . boot with radeon.modeset=0 (thus: disable radeon driver)
    -> screen o.k.; NO flickering
  . then sudo modprobe -v radeon modeset=1
    -> and the flickering starts ...
Comment 5 Werner Lueckel 2018-10-23 17:07:33 UTC
Created attachment 142156 [details]
dmesg Ubuntu14.04, Kernel4.4.0-133, radeon 2.43.0, screen flickering

... and I found out that the screen-flickering already starts with
VERSION="14.04.5 LTS, Trusty Tahr"
kernel: 4.4.0-133-generic
radeon 2.43.0

see the attached dmesg14.04_4.4.0-133.txt
Comment 6 Werner Lueckel 2018-10-24 13:29:58 UTC
Additional Information:

- I have the same flickering screen with

  Debian Life CD: UBCD-life
    Linux version 3.16.0-4-586
    [drm] Initialized radeon 2.39.0 20080528
Comment 7 Werner Lueckel 2018-10-30 15:54:54 UTC
some more tests with different systems give the following table:

sorted by radeon-version
system                                kernel            radeon          result
-------------------------             -----------       --------        --------
UBUNTU 14.04.5 LTS, Trusty Tahr       3.13.0-161        2.36.0          O.K.
puppy_tahr 6.0.5                      3.14.56           2.37.0          O.K.
puppy_slacko 6.3.2                    3.14.55           2.37.0          O.K
UBCD                                  3.16.0            2.39.0          FLICKER
puppy_xenialpup 7.5                   4.4.95            2.43.0          FLICKER
UBUNTU 14.04.5 LTS, Trusty Tahr       4.4.0-133         2.43.0          FLICKER
UBUNTU 18.04.1 LTS (Bionic Beaver)    4.15.0-36         2.50.0          FLICKER

so the problem seems to start with a radeon.ko driver > 2.37.0;
I wonder how the radeon-version 2.38.0 would work, but, so far, I havn't 
found a system including it.
Comment 8 Werner Lueckel 2018-11-04 14:41:20 UTC
more tests with flickering screen:

- check modelines "xvidtune -show -display :0"
  14.04 trusty (NO flickering)
  "1680x1050" 122.00 1680 1712 1776 1904 1050 1051 1054 1066 -hsync -vsync
  18.04.1 LTS (Flickering screen)
  "1680x1050" 122.00 1680 1712 1776 1904 1050 1051 1054 1066 -hsync -vsync
  -> exactly the same

- on 18.04.1 LTS 
  (1) with flickering grafic screen:
  repeatedly switch the screen-mode (xrandr): 
    to 1440x900 and back to 1680x1050
  -> typically after 2...5 repetitions the screen is o.k. and stops flickering

  (2) BUT: when the screen awakes from "sleep" -> the flickering starts again!
      switch to text-console (F1) -> flickers too!
      switch back to grafic (F7) -> flickering continues

   the I may continue with (1) 
   OR (frustrated): 
   BOOT 14.04 trusty; which still works fine; excellent grafic; never flickers;
   ... and start working!

- BUT: what can I do when support for "14.04 trusty" ends?
Comment 9 Werner Lueckel 2018-11-04 14:43:28 UTC
(In reply to Alex Deucher from comment #1)
> Any chance you can narrow down when the regression occurred and bisect it
> using git?  Please attach your dmesg output and xorg log (if using X).

I tried to narrow down the flickering issue making several tests; see my comments below.
Comment 10 Werner Lueckel 2018-11-04 14:48:47 UTC
(In reply to Alex Deucher from comment #1)
> Any chance you can narrow down when the regression occurred and bisect it
> using git?  Please attach your dmesg output and xorg log (if using X).

... sorry, by comments are not below, but "above" ...
Comment 11 Klaus Weiss 2018-12-04 14:39:31 UTC
(In reply to Werner Lueckel from comment #8)
> 
> - BUT: what can I do when support for "14.04 trusty" ends?

Try radeon.new_pll=0
Comment 12 Werner Lueckel 2018-12-07 16:40:37 UTC
thank you for your tip, but radeon.new_pll=0 gives me
... radeon: unknown parameter 'new_pll' ignored
And: I cannot find 'new_pll' in 'modinfo -p radeon';
So new_pll seems to be (no longer?) a radeon parameter.


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