Em Wed, 7 Jun 2017 22:17:50 +0200 Matthias Schwarzott <zzam@xxxxxxxxxx> escreveu: > Am 07.06.2017 um 20:23 schrieb Mauro Carvalho Chehab: > > Em Tue, 9 May 2017 06:56:25 +0200 > > Matthias Schwarzott <zzam@xxxxxxxxxx> escreveu: > > > >> 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 > > > > Well, if you build your Kernel with VB2 compiled, you'll have it. > > > Sure. > > So my question is: > How good do the kernel origin vb2 and the media_build vb2 play together? > > Will modprobe always choose the media_build one? > Or will "make install" just overwrite the original file? make install *should* overwrite the old one. If not, then there's a problem at the media-build makefile [1]. [1] or, if you're using a Kernel built by some distro, they choose to store the media drivers on some other random directory that it is not known by v4l/scripts/make_makefile.pl. > > >> 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? > > > > (1) is probably simpler, but you would need to play with the building > > system in order to identify if the current Kernel has it enabled or not. > > That could be tricky. > > > > I suspect people won't accept (2), as it doesn't make sense upstream. > > Well, it would be equivalent to options like CRC16 in folder lib. You can try to submit it to mm maintainers. I'm just saying that they may not be too receptive to a patch meant to solve an OOT build, specially because it will open a new item at the mm menu with should never be touched, as it is automatically selected. Thanks, Mauro
