Graphics Driver Nouveau problems on 20.04

[hstoellinger]

Hello,
Since upgrading to Focal Fossa a couple of weeks ago, I experience occasional screen freezes, which necessitate a reboot. I am on a rather "old" Sony laptop (see inxi -F output below). On 19.10 I used the NVIDIA-graphics driver (340.108). It worked like a charm. Reading that this driver isn't supported anymore on 20.04, I had to revert to the Nouveau driver. Are there any known issues with that?
inxi -F returns the following:

System:    Host: hslaptop Kernel: 5.4.0-33-generic x86_64 bits: 64 Desktop: KDE Plasma 5.18.5 
             Distro: Ubuntu 20.04 LTS (Focal Fossa) 
Machine:   Type: Laptop System: Sony product: VGN-AW11M_H v: C6010CXT serial: <superuser/root required> 
             Mobo: Sony model: VAIO serial: <superuser/root required> BIOS: American Megatrends v: R0200Y2 date: 08/12/2008 
Battery:    ID-1: BAT0 charge: 71.4 Wh condition: 72.2/73.3 Wh (98%) 
CPU:        Topology: Dual Core model: Intel Core2 Duo P8400 bits: 64 type: MCP L2 cache: 3072 KiB 
             Speed: 1596 MHz min/max: 1600/2267 MHz Core speeds (MHz): 1: 1596 2: 1596 
Graphics:  Device-1: NVIDIA G98M [GeForce 9300M GS] driver: nouveau v: kernel 
             Display: x11 server: X.Org 1.20.8 driver: modesetting unloaded: fbdev,vesa resolution: 1680x945~60Hz 
             OpenGL: renderer: NV98 v: 3.3 Mesa 20.0.4 
Audio:      Device-1: Intel 82801I HD Audio driver: snd_hda_intel 
            Sound Server: ALSA v: k5.4.0-33-generic

For comparison reasons, the same inxi -F output for 19.10:

System:    Host: hslaptop Kernel: 5.3.0-55-generic x86_64 bits: 64 Desktop: KDE Plasma 5.18.3 
         Distro: Ubuntu 19.10 (Eoan Ermine) 
Machine:   Type: Laptop System: Sony product: VGN-AW11M_H v: C6010CXT serial: <root required> 
         Mobo: Sony model: VAIO serial: <root required> BIOS: American Megatrends v: R0200Y2 date: 08/12/2008 
Battery:   ID-1: BAT0 charge: 71.4 Wh condition: 72.2/73.3 Wh (98%) 
CPU:       Topology: Dual Core model: Intel Core2 Duo P8400 bits: 64 type: MCP L2 cache: 3072 KiB 
         Speed: 1596 MHz min/max: 1600/2267 MHz Core speeds (MHz): 1: 1596 2: 1596 
Graphics:  Device-1: NVIDIA G98M [GeForce 9300M GS] driver: nvidia v: 340.108 
         Display: x11 server: X.Org 1.20.5 driver: nvidia resolution: 1680x945~60Hz 
         OpenGL: renderer: GeForce 9300M GS/PCIe/SSE2 v: 3.3.0 NVIDIA 340.108 
Audio:     Device-1: Intel 82801I HD Audio driver: snd_hda_intel 
         Sound Server: ALSA v: k5.3.0-55-generic

By the way, sound doesn't seem to work well either on 20.04.
Thanks in advance for any hints.
H. Stoellinger

[claydoh]

the 340 driver is still in the 20.04 repos, Nvidia dropped support for it past the 5.4 kernel, which is what Focal has currently. As long as you stay on that kernel, you can have the closed source nvidia driver.

otherwise it probably will take a bit of research and patience. There are a fair number of grub boot parameters that may help, such as nouveau.noaccel=1 but I have zero idea if any specific one will work on your specific system

[hstoellinger]

Thanks for the quick answer! I installed package "nvidia-340_340.108-0ubuntu2_amd64.deb" from ubuntu.packages.com. In the process dkms also got installed "automagically". The system works after re-booting. Let's see whether the occasional freezes are gone now.
Regards from Salzburg, Austria