cryptsetup requires newer i915 firmwares that is not included in LTS 20.04.3

[Benjamin Hokma]

I've made my packages up to date, and my current linux-firmware version is for Ubuntu 'focal-updates' (AKA 20.04.3 LTS), which can be shown with the command below:
########################################################################
$ apt list -a linux-firmware
Listing... Done
linux-firmware/focal-updates,focal-updates,now 1.187.20 all [installed]
linux-firmware/focal,focal 1.187 all
########################################################################

Same can be done for cryptsetup, showing the package is also intended for 'focal-updates':
########################################################################
$ apt list -a cryptsetup
Listing... Done
cryptsetup/focal-updates,now 2:2.2.2-3ubuntu2.3 amd64 [installed]
cryptsetup/focal-security 2:2.2.2-3ubuntu2.2 amd64
cryptsetup/focal 2:2.2.2-3ubuntu2 amd64

cryptsetup/focal-updates 2:2.2.2-3ubuntu2.3 i386
cryptsetup/focal-security 2:2.2.2-3ubuntu2.2 i386
cryptsetup/focal 2:2.2.2-3ubuntu2 i386
########################################################################

However, when installing cryptsetup, it wants newer i915 drivers from newer linux-firmware, which is not included until Ubuntu 21.04 'hirsute':
########################################################################
W: Possible missing firmware /lib/firmware/i915/skl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/bxt_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/glk_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/kbl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/cml_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/icl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/ehl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/ehl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/tgl_huc_7.5.0.bin for module i915
W: Possible missing firmware /lib/firmware/i915/tgl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/tgl_huc_7.5.0.bin for module i915
W: Possible missing firmware /lib/firmware/i915/tgl_guc_49.0.1.bin for module i915
W: Possible missing firmware /lib/firmware/i915/dg1_dmc_ver2_02.bin for module i915
########################################################################

Comparison of different versions of linux-firmware:

1. Filelist for older linux-firmware 'focal-update' (https://packages.ubuntu.com/focal-updates/all/linux-firmware/filelist):
...
/lib/firmware/i915/bxt_guc_32.0.3.bin
/lib/firmware/i915/bxt_guc_33.0.0.bin
/lib/firmware/i915/bxt_guc_ver8_7.bin
/lib/firmware/i915/bxt_guc_ver9_29.bin
...

2. Filelist for newer linux-firmware 'hirsute' (https://packages.ubuntu.com/hirsute/all/linux-firmware/filelist):
...
/lib/firmware/i915/bxt_guc_32.0.3.bin
/lib/firmware/i915/bxt_guc_33.0.0.bin
/lib/firmware/i915/bxt_guc_49.0.1.bin
/lib/firmware/i915/bxt_guc_ver8_7.bin
/lib/firmware/i915/bxt_guc_ver9_29.bin
...

ProblemType: Bug
DistroRelease: Ubuntu 20.04
Package: cryptsetup 2:2.2.2-3ubuntu2.3
ProcVersionSignature: Ubuntu 5.11.0-40.44~20.04.2-generic 5.11.22
Uname: Linux 5.11.0-40-generic x86_64
NonfreeKernelModules: nvidia_modeset nvidia
ApportVersion: 2.20.11-0ubuntu27.21
Architecture: amd64
CasperMD5CheckResult: skip
CurrentDesktop: KDE
Date: Sun Nov 28 16:40:51 2021
InstallationDate: Installed on 2021-11-28 (0 days ago)
InstallationMedia: Ubuntu 20.04.3 LTS "Focal Fossa" - Release amd64 (20210819)
SourcePackage: cryptsetup
UpgradeStatus: No upgrade log present (probably fresh install)
cmdline: BOOT_IMAGE=/vmlinuz-5.11.0-40-generic root=UUID=e66d35ea-faa2-41f9-b4b2-4635f88bf45d ro quiet splash vt.handoff=7
crypttab: # <target name> <source device> <key file> <options>

[Juerg Haefliger (juergh)]

This is just a warning when the initrd is regenerated that some firmwares might be missing. In this case it's graphics firmware which has nothing to do with cryptsetup.