screen tearing and redraw in ubuntu 20.04 LTS

I have used ubuntu 21.04 before on this device and reported a bug and it is solved by making psr value to 0. but in ubuntu 20.04LTS is not working.

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: xorg 1:7.7+19ubuntu14
ProcVersionSignature: Ubuntu 5.11.0-25.27~20.04.1-generic 5.11.22
Uname: Linux 5.11.0-25-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
.proc.driver.nvidia.capabilities.gpu0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/capabilities/gpu0'
.proc.driver.nvidia.capabilities.mig: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/capabilities/mig'
.proc.driver.nvidia.gpus.0000.30.00.0: Error: [Errno 21] Is a directory: '/proc/driver/nvidia/gpus/0000:30:00.0'
.proc.driver.nvidia.registry: Binary: ""
.proc.driver.nvidia.suspend: suspend hibernate resume
.proc.driver.nvidia.suspend_depth: default modeset uvm
.proc.driver.nvidia.version:
 NVRM version: NVIDIA UNIX x86_64 Kernel Module 460.91.03 Fri Jul 2 06:04:10 UTC 2021
 GCC version:
ApportVersion: 2.20.11-0ubuntu27.16
Architecture: amd64
CasperMD5CheckResult: skip
CompositorRunning: None
Date: Sun Aug 8 13:57:13 2021
DistUpgraded: Fresh install
DistroCodename: focal
DistroVariant: ubuntu
ExtraDebuggingInterest: Yes, if not too technical
GraphicsCard:
 Intel Corporation Iris Plus Graphics G7 [8086:8a52] (rev 07) (prog-if 00 [VGA controller])
   Subsystem: Lenovo Iris Plus Graphics G7 [17aa:3a34]
   Subsystem: Lenovo GP107M [GeForce MX350] [17aa:3a34]
InstallationDate: Installed on 2021-08-08 (0 days ago)
InstallationMedia: Ubuntu 20.04.2.0 LTS "Focal Fossa" - Release amd64 (20210209.1)
MachineType: LENOVO 82A1
ProcEnviron:
 LANGUAGE=en_IN:en
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_IN
 SHELL=/bin/bash
ProcKernelCmdLine: BOOT_IMAGE=/boot/vmlinuz-5.11.0-25-generic root=UUID=24316984-3147-43ba-aac0-f4497301192e ro quiet splash vt.handoff=7
SourcePackage: xorg
Symptom: display
UpgradeStatus: No upgrade log present (probably fresh install)
dmi.bios.date: 05/27/2021
dmi.bios.release: 1.32
dmi.bios.vendor: LENOVO
dmi.bios.version: DHCN32WW
dmi.board.asset.tag: ���������������
dmi.board.name: LNVNB161216
dmi.board.vendor: LENOVO
dmi.board.version: SDK0Q55722 WIN
dmi.chassis.asset.tag: ���������������
dmi.chassis.type: 10
dmi.chassis.vendor: LENOVO
dmi.chassis.version: Yoga Slim 7 14IIL05
dmi.ec.firmware.release: 1.29
dmi.modalias: dmi:bvnLENOVO:bvrDHCN32WW:bd05/27/2021:br1.32:efr1.29:svnLENOVO:pn82A1:pvrYogaSlim714IIL05:rvnLENOVO:rnLNVNB161216:rvrSDK0Q55722WIN:cvnLENOVO:ct10:cvrYogaSlim714IIL05:
dmi.product.family: Yoga Slim 7 14IIL05
dmi.product.name: 82A1
dmi.product.sku: LENOVO_MT_82A1_BU_idea_FM_Yoga Slim 7 14IIL05
dmi.product.version: Yoga Slim 7 14IIL05
dmi.sys.vendor: LENOVO
version.compiz: compiz N/A
version.libdrm2: libdrm2 2.4.105-3~20.04.1
version.libgl1-mesa-dri: libgl1-mesa-dri 20.2.6-0ubuntu0.20.04.1
version.libgl1-mesa-glx: libgl1-mesa-glx N/A
version.nvidia-graphics-drivers: nvidia-graphics-drivers-* N/A
version.xserver-xorg-core: xserver-xorg-core 2:1.20.9-2ubuntu1.2~20.04.1
version.xserver-xorg-input-evdev: xserver-xorg-input-evdev N/A
version.xserver-xorg-video-ati: xserver-xorg-video-ati 1:19.1.0-1
version.xserver-xorg-video-intel: xserver-xorg-video-intel 2:2.99.917+git20200226-1
version.xserver-xorg-video-nouveau: xserver-xorg-video-nouveau 1:1.0.16-1