Make fails

[thamognya]

make -C /lib/modules/5.16.11-gentoo-x86_64/build M=/home/jeff/Documents/video-driver/facetimehd-0.5.7 modules
make[1]: Entering directory '/usr/src/linux-5.16.11-gentoo'
warning: the compiler differs from the one used to build the kernel
  The kernel was built by: x86_64-pc-linux-gnu-gcc (Gentoo 11.2.0 p1) 11.2.0
  You are using:           gcc (Gentoo 11.2.0 p1) 11.2.0
  MODPOST /home/jeff/Documents/video-driver/facetimehd-0.5.7/Module.symvers
ERROR: modpost: "vb2_dma_sg_memops" [/home/jeff/Documents/video-driver/facetimehd-0.5.7/facetimehd.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:134: /home/jeff/Documents/video-driver/facetimehd-0.5.7/Module.symvers] Error 1
make[2]: *** Deleting file '/home/jeff/Documents/video-driver/facetimehd-0.5.7/Module.symvers'
make[1]: *** [Makefile:1761: modules] Error 2
make[1]: Leaving directory '/usr/src/linux-5.16.11-gentoo'
make: *** [Makefile:12: all] Error 2

This is my error

I am running gentoo and am not too sure what went wrong.

I am using this guide rather than the outdated ebuild:

https://gist.github.com/johnjeffers/3006011ec7767a4101cdd118e8d64290#facetime-camera

[ricjcosme]

Having the same problem in RHEL 9, kernel 5.14.0-70.13.1.el9_0.x86_64

make -C /lib/modules/5.14.0-70.13.1.el9_0.x86_64/build M=/home/rc/Downloads/facetimehd modules
make[1]: Entering directory '/usr/src/kernels/5.14.0-70.13.1.el9_0.x86_64'
  CC [M]  /home/rc/Downloads/facetimehd/fthd_ddr.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_hw.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_drv.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_ringbuf.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_isp.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_v4l2.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_buffer.o
  CC [M]  /home/rc/Downloads/facetimehd/fthd_debugfs.o
  LD [M]  /home/rc/Downloads/facetimehd/facetimehd.o
  MODPOST /home/rc/Downloads/facetimehd/Module.symvers
ERROR: modpost: "vb2_dma_sg_memops" [/home/rc/Downloads/facetimehd/facetimehd.ko] undefined!
make[2]: *** [scripts/Makefile.modpost:150: /home/rc/Downloads/facetimehd/Module.symvers] Error 1
make[2]: *** Deleting file '/home/rc/Downloads/facetimehd/Module.symvers'
make[1]: *** [Makefile:1777: modules] Error 2
make[1]: Leaving directory '/usr/src/kernels/5.14.0-70.13.1.el9_0.x86_64'
make: *** [Makefile:12: all] Error 2

[GlenWalker2]

I have a slightly different kernel but the exact same problem.

5.14.0-162.12.1.el9_1.x86_64

I'm also on RedHat (RHEL) 9. Is it some quirk in the way our kernel has been built? Will we have to build another kernel with different flags set? Its been a long time since I've built a kernel so will have to refresh my memory a bit.

Have hunted around in the source code and on the web and cannot work out what is going on. If I'm understanding the code correctly then the source file "fthd_v4l2.c" includes the header "media/videobuf2-dma-sg.h" which declares vb2_dma_sg_memops as:

extern const struct vb2_mem_ops vb2_dma_sg_memops;

and I can only assume that it hasn't been defined and included in the kernel as an available function. What do you think?

[GlenWalker2]

An update today and I'm going to keep looking but it appears my suspicions might be right about it not being enabled in the kernel. This post is related: http://github.com/toaster/gentoo-overlay/issues/4

[scheepers]

Here too, but on Ubuntu

make -C /lib/modules/5.19.0-42-generic/build M=/home/me/bcwc_pcie modules
make[1]: Entering directory '/usr/src/linux-headers-5.19.0-42-generic'
warning: the compiler differs from the one used to build the kernel
  The kernel was built by: x86_64-linux-gnu-gcc (Ubuntu 11.3.0-1ubuntu1~22.04.1) 11.3.0
  You are using:           gcc (Ubuntu 11.3.0-1ubuntu1~22.04.1) 11.3.0
make[1]: Leaving directory '/usr/src/linux-headers-5.19.0-42-generic'

[ellandisan]

I have same situtation with same error , do you have any resolution for this ?
warning: the compiler differs from the one used to build the kernel
The kernel was built by: x86_64-linux-gnu-gcc-12 (Ubuntu 12.3.0-1ubuntu1~22.04) 12.3.0
You are using:
CC [M] /home/jakub/bcwc_pcie/fthd_ddr.o