Correct way to build kernel with hardware support fix patches - Ubuntu 22.04 LTS - 5.15.0-50

I think the issue is because the Ubuntu / Debian release kernel comes with some extra patches or may be due to the configuration difference in installed kernel version and the one from kernel.org.

Note that 5.15.74 is a mainline Linux version and mentioned 5.15.0-50 is an Ubuntu version, both are not same.

As all other functionalities are working in source kernel, it is better to build a custom patched kernel from source kernel to correct the issue.

Steps to follow,

1. Enable source code repositories, this will add needed deb-src lines in /etc/apt/sources.list.

   

2. Install the tools require to compile the packages from source code,also ensure around 20+ GB disc space before building.

   # To install build tools
   sudo apt update
   sudo apt build-dep linux linux-image-$(uname -r)
   
   sudo apt install libncurses-dev gawk flex bison openssl libssl-dev dkms libelf-dev libudev-dev libpci-dev libiberty-dev autoconf llvm build-essential libncurses5-dev gcc bc dwarves
   

3. Obtaining the source for Ubuntu release: The source code which generated a specific binary package may be obtained using the apt source <package> command, to get other versions check this - official documentation, [ ref-2 ]

   # switch to root
   sudo su
   
   # get the current kernel source downloaded and extracted (ignore the end user warning)
   apt source linux-image-unsigned-$(uname -r)
   
   cd /path/to/linux-<version>/
   
   # Give all user execution permissions to scripts (Important, otherwise error will be thrown even if you are running them as root)
   chmod a+x debian/scripts/*
   chmod a+x -R ./scripts
   

4. Download and apply the patch,

   patch -p1 < ~/Downloads/<patch-name>.patch
   

5. Copy the existing configurations,

   cp /boot/config-$(uname -r) ./.config
   
   # update config for new kernel
   make oldconfig
   

6. Compile the kernel, [ref]

   make -j16 deb-pkg LOCALVERSION=-custom
   

   You want to replace -j16 with however many threads your processor has (use getconf _NPROCESSORS_ONLN to get the number). the “LOCALVERSION” option can be anything you want. It’s only there for documentation purposes. Now your kernel should be compiling. This could take a while, depending on your hardware (1-2 hours)

7. Install the new patched kernel, update grub and reboot to new kernel

   # change to parent dir
   cd ..
   
   dpkg -i *.deb
   
   update-grub
   reboot
   

   Use the mainline tool to remove old kernel,