Arch Linux User Repository

I finally had time to investigate the issue. It looks like that as of 11.5, the DesktopVideoHelper.service has to be running for the capture card to work properly.

Would you consider adding -Wno-error=strict-prototypes flag to the Makefile? This is needed to prevent build failures when compiling against Clang/LLVM-based kernels, as Clang treats function declarations without prototypes as an error by default.

This change would suppress those specific warnings being treated as fatal, without impacting builds on GCC or weakening general warning coverage.

Temporary workaround: edit /usr/src/blackmagic-io-14.4.1a4/dkms.conf and /usr/src/blackmagic-14.4.1a4/dkms.conf and change MAKE="make KERNELRELEASE=$kernelver" to MAKE="make KERNELRELEASE=$kernelver EXTRA_CFLAGS="-Wno-error=strict-prototypes""

also a friendly reminder to check for firmware updates when troubleshooting the driver. in this case a firmware update was required (for a Decklink Duo 2), which made it not appear in BlackmagicDesktopVideoSetup or other softwares, even if the driver was functionning.

once the driver is working (and service running), DesktopVideoUpdateTool -l will list outdated cards that are otherwise unreported by BlackmagicDesktopVideoSetup.

the fix works on 6.13.2-arch1-1 but it did not compile for 6.12.13-1-lts with

libbpf: failed to get e_shstrndx from vmlinux Fail
ed to parse base BTF 'vmlinux': -4001 

i don't think this is a Decklink issue; this machine was a bit long in the updates (perhaps 9 months) but just in case someone else faces the same thing: had to run sudo pacman -S linux-lts-headers (even if it was already installed and fresh out of an -Syu prior to trying to update Decklink) which triggered DKMS and compiled correctly for LTS. don't know enough about PKGBUILD to suggest if something should be included to prevent such issues.

Thank you for the fix and sorry for the delay. I just pushed the fix

Can confirm module fails to build with 6.13. I was able to get the module to build by modifying the source makefile in /var/lib/dkms/... to include a rule which copies the pre-compiled object files bmd-support.o_shipped and blackmagic.o_shipped like so:

bmd-support.o: bmd-support.o_shipped
    cp bmd-support.o_shipped bmd-support.o

Capture card works as expected after dkms autoinstall. Not a C dev, and not sure what changed, but hopefully this will help someone.

The module no longer builds for me with kernel 6.13.

# dkms install --no-depmod blackmagic-io/14.4.1a4 -k 6.13.2-arch1-1
Sign command: /usr/lib/modules/6.13.2-arch1-1/build/scripts/sign-file
Signing key: /var/lib/dkms/mok.key
Public certificate (MOK): /var/lib/dkms/mok.pub

Cleaning build area... done.
Building module(s)...(bad exit status: 2)
Failed command:
make -j48 KERNELRELEASE=6.13.2-arch1-1 KERNELRELEASE=6.13.2-arch1-1

Error! Bad return status for module build on kernel: 6.13.2-arch1-1 (x86_64)
Consult /var/lib/dkms/blackmagic-io/14.4.1a4/build/make.log for more information.

And in /var/lib/dkms/blackmagic-io/14.4.1a4/build/make.log:

make[4]: *** No rule to make target 'blackmagic.o', needed by 'blackmagic-io.o'.

Any ideas?

Building the module is broken on 6.13.1 kernel

make -C /lib/modules/6.13.1-arch1-1/build M=/var/lib/dkms/blackmagic-io/14.4.1a4/build
make[1]: Entering directory '/usr/lib/modules/6.13.1-arch1-1/build'
make[2]: Entering directory '/var/lib/dkms/blackmagic-io/14.4.1a4/build'
  CC [M]  bmio_client.o
  CC [M]  bmio_dev.o
  CC [M]  bmio_device.o
  CC [M]  bmio_driver.o
  CC [M]  bmio_serial.o
  CC [M]  bmio_export.o
  CC [M]  bmio_pci_ids.o
  CC [M]  bm_locks.o
  CC [M]  bm_mm.o
  CC [M]  bm_pci.o
make[4]: *** No rule to make target 'blackmagic.o', needed by 'blackmagic-io.o'.  Stop.
make[4]: *** Waiting for unfinished jobs....
  CC [M]  bm_util.o
bm_util.c:123:9: warning: "MAX" redefined
  123 | #define MAX(a, b) ((a) > (b) ? (a) : (b))
      |         ^~~
In file included from /usr/lib/modules/6.13.1-arch1-1/build/include/linux/kernel.h:28,
                from /usr/lib/modules/6.13.1-arch1-1/build/include/linux/cpumask.h:11,
                from /usr/lib/modules/6.13.1-arch1-1/build/arch/x86/include/asm/paravirt.h:21,
                from /usr/lib/modules/6.13.1-arch1-1/build/arch/x86/include/asm/cpuid.h:64,
                from /usr/lib/modules/6.13.1-arch1-1/build/arch/x86/include/asm/processor.h:19,
                from /usr/lib/modules/6.13.1-arch1-1/build/include/linux/sched.h:13,
                from /usr/lib/modules/6.13.1-arch1-1/build/include/linux/delay.h:13,
                from bm_util.c:27:
/usr/lib/modules/6.13.1-arch1-1/build/include/linux/minmax.h:330:9: note: this is the location of the previous definition
  330 | #define MAX(a,b) __cmp(max,a,b)
      |         ^~~
make[3]: *** [/usr/lib/modules/6.13.1-arch1-1/build/Makefile:1989: .] Error 2
make[2]: *** [/usr/lib/modules/6.13.1-arch1-1/build/Makefile:251: __sub-make] Error 2
make[2]: Leaving directory '/var/lib/dkms/blackmagic-io/14.4.1a4/build'
make[1]: *** [Makefile:251: __sub-make] Error 2
make[1]: Leaving directory '/usr/lib/modules/6.13.1-arch1-1/build'
make: *** [Makefile:47: all] Error 2

Hi francisqureshi, I don't own a working capture card anymore so I only check if the driver builds on linux and linux-lts but I cannot check if it works fine when in use.

In addition to enabling DesktopVideoHelper.service, I also had to put ibt=off in my kernel cmdline to keep the driver from crashing on kernel 6.11.3-arch1-1.

Hey there goldensuneur, thanks for all your efforts. Is it possible to use this with the latest kernels? Or more importantly, what version kernel do you recommend to use this decklink package?