[Bug 108514] heavy screen flickering with Mobility Radeon X1600 and kernel version onwards 3.13

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

Bug ID: 108514
Summary: heavy screen flickering with Mobility Radeon X1600 and
kernel version onwards 3.13
Product: DRI
Version: unspecified
Hardware: x86-64 (AMD64)
OS: Linux (All)
Status: NEW
Severity: normal
Priority: medium
Component: DRM/Radeon
Assignee: dri-***@lists.freedesktop.org
Reporter: ***@googlemail.com

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: ***@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?

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #1 from Alex Deucher <***@gmail.com> ---
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).

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #2 from Werner Lueckel <***@googlemail.com> ---
Created attachment 142154
--> https://bugs.freedesktop.org/attachment.cgi?id=142154&action=edit
dmesg Ubuntu14.04, Kernel3.13.0-160, radeon 2.36.0, screen O.K.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #3 from Werner Lueckel <***@googlemail.com> ---
Created attachment 142155
--> https://bugs.freedesktop.org/attachment.cgi?id=142155&action=edit
dmesg Ubuntu18.04, Kernel4.15.0-36, radeon 2.50.0, screen flickering

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #4 from Werner Lueckel <***@googlemail.com> ---
- 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 ...

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #5 from Werner Lueckel <***@googlemail.com> ---
Created attachment 142156
--> https://bugs.freedesktop.org/attachment.cgi?id=142156&action=edit
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

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #6 from Werner Lueckel <***@googlemail.com> ---
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

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #7 from Werner Lueckel <***@googlemail.com> ---
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.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #8 from Werner Lueckel <***@googlemail.com> ---
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?

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #9 from Werner Lueckel <***@googlemail.com> ---
(In reply to Alex Deucher from comment #1)

Post by b***@freedesktop.org
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.

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #10 from Werner Lueckel <***@googlemail.com> ---
(In reply to Alex Deucher from comment #1)

Post by b***@freedesktop.org
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" ...

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #11 from Klaus Weiss <***@seznam.cz> ---
(In reply to Werner Lueckel from comment #8)

Post by b***@freedesktop.org
- BUT: what can I do when support for "14.04 trusty" ends?

Try radeon.new_pll=0

[b***@freedesktop.org]

https://bugs.freedesktop.org/show_bug.cgi?id=108514

--- Comment #12 from Werner Lueckel <***@googlemail.com> ---
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.