nouveau: display scans black from botton to top periodically and flashes on DE.

[Jarno Suni]

When I switch to any virtual terminal (TTY1-TTY6 in Xubuntu) display will be filled with black from bottom to up. Then text is drawn again, and then the same happens again. Besides the screen is flashing sometimes like in login screen of the DE or when I use Google Maps on Firefox.

Reproduceable: not always

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: linux-image-5.0.0-25-generic 5.0.0-25.26~18.04.1
ProcVersionSignature: Ubuntu 5.0.0-25.26~18.04.1-generic 5.0.18
Uname: Linux 5.0.0-25-generic x86_64
NonfreeKernelModules: wl
ApportVersion: 2.20.9-0ubuntu7.7
Architecture: amd64
CurrentDesktop: XFCE
Date: Thu Aug 22 09:57:13 2019
EcryptfsInUse: Yes
InstallationDate: Installed on 2017-01-05 (958 days ago)
InstallationMedia: Xubuntu 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719)
SourcePackage: linux-signed-hwe
UpgradeStatus: No upgrade log present (probably fresh install)

[lotuspsychje (lotuspsychje)]

Have you tryed another kernel test?
what kind of chipset is your graphics card please?
can you upload your dmesg logs?

[Jarno Suni (jarnos)]

$ sudo lspci -vvvxxx | awk 'BEGIN{RS="\n\n"}/ VGA /'
02:00.0 VGA compatible controller: NVIDIA Corporation C79 [GeForce 9400M] (rev b1) (prog-if 00 [VGA controller])
 Subsystem: Apple Inc. MacBook5,1
 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+
 Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx-
 Latency: 0, Cache Line Size: 256 bytes
 Interrupt: pin A routed to IRQ 25
 Region 0: Memory at d2000000 (32-bit, non-prefetchable) [size=16M]
 Region 1: Memory at c0000000 (64-bit, prefetchable) [size=256M]
 Region 3: Memory at d0000000 (64-bit, prefetchable) [size=32M]
 Region 5: I/O ports at 1000 [size=128]
 Expansion ROM at d3000000 [disabled] [size=128K]
 Capabilities: [60] Power Management version 2
  Flags: PMEClk- DSI- D1- D2- AuxCurrent=0mA PME(D0-,D1-,D2-,D3hot-,D3cold-)
  Status: D0 NoSoftRst- PME-Enable- DSel=0 DScale=0 PME-
 Capabilities: [68] MSI: Enable+ Count=1/1 Maskable- 64bit+
  Address: 00000000fee01004 Data: 4024
 Kernel driver in use: nouveau
 Kernel modules: nvidiafb, nouveau
00: de 10 63 08 07 04 10 00 b1 00 00 03 40 00 00 00
10: 00 00 00 d2 0c 00 00 c0 00 00 00 00 0c 00 00 d0
20: 00 00 00 00 01 10 00 00 00 00 00 00 6b 10 aa 00
30: 00 00 00 d3 60 00 00 00 00 00 00 00 00 01 00 00
40: 6b 10 aa 00 00 00 00 00 00 00 00 00 00 00 00 00
50: 00 00 00 00 01 00 00 00 ce d6 23 00 00 00 00 00
60: 01 68 02 00 00 00 00 00 05 00 81 00 04 10 e0 fe
70: 00 00 00 00 24 40 00 00 00 00 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 33 03 00 00 00 93 57 00 00 0f 00 00 80
a0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
b0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 08 00 00 00 01 00 00 00 00 00

[Jarno Suni (jarnos)]

After I suspend to RAM end resume, and thereafter open a virtual terminal, there is no such scanning.

[Jarno Suni (jarnos)]

After I suspend to RAM end resume, and thereafter there is no flickering in LightDM login screen, either.

These thing seem to happen both on 4.15 and 5.0 kernels.

[lotuspsychje (lotuspsychje)]

Could you try: ubuntu-drivers list
and see if you can install an nvidia driver version instead of nouveau
and see if this bug remains?

[Jarno Suni (jarnos)]

Yes, nvidia-340 can be used with the hardware, but maybe not long: https://askubuntu.com/q/1146245/21005
I have not met such flickering problems with the nvidia driver, but virtual terminal can not be used at all (like this except only 9400 M here: https://devtalk.nvidia.com/default/topic/1038605/black-screen-on-virtual-console-with-geforce-9600m-gt-amp-9400-m/) and recovery kernel can not be booted. Besides, there are problems with recovering from suspend to RAM. But I can use VDPAU acceleration with nvidia driver unlike with nouveau.

[Jarno Suni (jarnos)]

As for #3, something changes in the output before and after suspend-resume, and even between various suspend-resumes.