evdi-dkms FTBS with the new hwe linux 6.8 in jammy

[Andrea Righi]

[Impact]

/var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_fb.c: In function ‘evdifb_create’:
/var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_fb.c:421:23: error: ‘FBINFO_DEFAULT’ undeclared (first use in this function)
  421 | info->flags = FBINFO_DEFAULT;
      | ^~~~~~~~~~~~~~
/var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_fb.c:421:23: note: each undeclared identifier is reported only once for each function it appears in
make[2]: *** [scripts/Makefile.build:243: /var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_fb.o] Error 1
make[2]: *** Waiting for unfinished jobs....
In file included from /var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_drm_drv.c:16:
/var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_drm_drv.c:41:27: error: ‘DRM_UNLOCKED’ undeclared here (not in a function); did you mean ‘VM_LOCKED’?
   41 | DRM_UNLOCKED),
      | ^~~~~~~~~~~~
./include/drm/drm_ioctl.h:155:26: note: in definition of macro ‘DRM_IOCTL_DEF_DRV’
  155 | .flags = _flags, \
      | ^~~~~~
make[2]: *** [scripts/Makefile.build:243: /var/lib/dkms/evdi/1.12.0+dfsg/build/evdi_drm_drv.o] Error 1

[Test case]

 $ sudo apt instal evdi-dkms

[Fix]

Backport the changes from the evdi-dkms module in Noble to properly support the new 6.8 kernel ABI.

[Regression potential]

The EVDI module can be used to control multiple screens. We may experience regressions related to graphics / monitors in systems that are using this module, especially with the new hwe 6.8 kernel.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: evdi-dkms 1.12.0+dfsg-0ubuntu2~22.04.3
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: Fri Jun 21 08:50:20 2024
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=C.UTF-8
 SHELL=/bin/bash
SourcePackage: evdi
UpgradeStatus: No upgrade log present (probably fresh install)

[Andrea Righi (arighi)]

Test build with GA kernel:

evdi.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/

Test build with new hwe kernel:

evdi.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/

[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.