Hi! Whenever I compile the media drivers using media_build against a recent kernel, I get this message when loading them: [ 5.848537] media: Linux media interface: v0.10 [ 5.881440] Linux video capture interface: v2.00 [ 5.881441] WARNING: You are using an experimental version of the media stack. ... [ 6.166390] videobuf2_memops: Unknown symbol put_vaddr_frames (err 0) [ 6.166394] videobuf2_memops: Unknown symbol get_vaddr_frames (err 0) [ 6.166396] videobuf2_memops: Unknown symbol frame_vector_destroy (err 0) [ 6.166398] videobuf2_memops: Unknown symbol frame_vector_create (err 0) That means I am not able to load any drivers being based on videobuf2_memops without manual actions. I used kernel 4.11.0, but it does not matter which kernel version exactly is used. My solution for that has been to modify mm/Kconfig of my kernel like this and then enable FRAME_VECTOR in .config diff --git a/mm/Kconfig b/mm/Kconfig index 9b8fccb969dc..cfa6a80d1a0a 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -701,7 +701,7 @@ config ZONE_DEVICE If FS_DAX is enabled, then say Y. config FRAME_VECTOR - bool + tristate "frame vector" config ARCH_USES_HIGH_VMA_FLAGS bool But I do not like that solution. I would prefer one of these solutions: 1. Have media_build apply its fallback the same way as for older kernels that do not even have the the FRAME_VECTOR support. 2. Get the above patch merged (plus description etc.). What do you think? Regards Matthias