ddcci-dkms FTBS with linux hwe 6.8 on jammy

[Andrea Righi]

[Impact]

/var/lib/dkms/ddcci/0.4.1/build/ddcci/ddcci.c:1677:9: error: implicit declaration of function ‘strlcpy’; did you mean ‘strscpy’? [-Werror=implicit-function-declaration]
 1677 | strlcpy(info->type, (outer_addr == DDCCI_DEFAULT_DEVICE_ADDR) ? "ddcci" : "ddcci-dependent", I2C_NAME_SIZE);
      | ^~~~~~~
      | strscpy
/var/lib/dkms/ddcci/0.4.1/build/ddcci/ddcci.c: At top level:
/var/lib/dkms/ddcci/0.4.1/build/ddcci/ddcci.c:1835:27: error: ‘I2C_CLASS_DDC’ undeclared here (not in a function); did you mean ‘I2C_CLASS_SPD’?
 1835 | .class = I2C_CLASS_DDC,
      | ^~~~~~~~~~~~~
      | I2C_CLASS_SPD
cc1: some warnings being treated as errors

[Test case]

 $ sudo apt install ddcci-dkms

[Fix]

Backport from Noble the required changes to properly support the new 6.8 kernel ABI.

[Regression potential]

DDC/CI is a driver for compatible monitors and their integration into the backlight system class. We may experience graphical regressions in systems that are using this particular driver.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: ddcci-dkms 0.4.1-3ubuntu3
ProcVersionSignature: User Name 6.8.0-35.35.1~22.04.1-lowlatency 6.8.4
Uname: Linux 6.8.0-35-lowlatency x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
CloudArchitecture: x86_64
CloudID: nocloud
CloudName: unknown
CloudPlatform: nocloud
CloudSubPlatform: config-disk (/dev/vdb)
Date: Tue Jun 18 09:22:45 2024
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: ddcci-driver-linux
UpgradeStatus: No upgrade log present (probably fresh install)

[Andrea Righi (arighi)]

Test build with the new 6.8 HWE kernel:

ddcci.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/6.8.0-35-lowlatency/updates/dkms/

ddcci-backlight.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/6.8.0-35-lowlatency/updates/dkms/

Test build with GA kernel 5.15:

ddcci.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.15.0-115-generic/updates/dkms/

ddcci-backlight.ko:
Running module version sanity check.
 - Original module
   - No original module exists within this kernel
 - Installation
   - Installing to /lib/modules/5.15.0-115-generic/updates/dkms/

[Robie Basak (racb)]

Please amend the Test Plan to make it clear that testing both the GA and HWE kernels is required. I expect to see this in the Test Plan for every HWE backport fix (and if it's not required then an explanation as to why).

I understand that I could just do this myself but it feels like every time I look at an HWE backport fix this isn't in the Test Plan, so I'm pushing back now to get this done properly from the beginning. That way there will be less effort for everyone at a time that the SRU queues are quite large and efficiency matters.