[elrepo-devel] kmod-video4linux for el6

[Phil Perry]

On 16/03/12 02:00, Gena Makhomed wrote:
> Hello, All!
>
> kmod-video4linux for el6:
> http://elrepo.org/bugs/view.php?id=247
>

Thanks for your contribution.

WRT some of the issues you document in your SPEC file, I'll copy them 
here and reply inline below:

#
# KNOWN BUGS:
#
# 
==============================================================================================================
#
# 1. /lib/firmware conflict/collision during rpm build process:
#
# if old version of package kmod-video4linux already installed,
# build of the new version of this package will fail with error:
# File not found: 
/home/rpmbuild/rpmbuild/BUILDROOT/video4linux-kmod-1.0.0-1.20120309.el6.cs.i386/lib/firmware
#
# WORKAROUND: remove old installed version of kmod-video4linux package 
before building new one.
#
# COMPLETE SOLUTION: none at this moment.
#
#

You must use a clean build system, ideally mock as only that will allow 
for reproducible builds.



==============================================================================================================
#
# 2. warning messages about unknown symbols during rpm install process:
#
# if kmod-alsa 1.0.25 installed:
#
# # yum install kmod-video4linux
#   Installing : kmod-video4linux-0.0-1.20120309.el6.cs.i686
# Working. This may take some time ...
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/kernel/drivers/media/video/soc_camera.ko 
needs unknown symbol video_device_shadow_get
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/kernel/drivers/media/video/soc_camera.ko 
needs unknown symbol video_register_device
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/weak-updates/alsa/snd-tea575x-tuner.ko 
needs unknown symbol video_register_device
# Done.
#
# if kmod-alsa 1.0.25 not installed:
#
# Working. This may take some time ...
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/kernel/drivers/media/video/soc_camera.ko 
needs unknown symbol video_device_shadow_get
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/kernel/drivers/media/video/soc_camera.ko 
needs unknown symbol video_register_device
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/weak-updates/video4linux/radio-miropcm20.ko 
needs unknown symbol snd_aci_cmd
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/weak-updates/video4linux/radio-miropcm20.ko 
needs unknown symbol snd_aci_get_aci
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/weak-updates/video4linux/radio-sf16fmr2.ko 
needs unknown symbol snd_tea575x_exit
# WARNING: 
/lib/modules/2.6.32-220.7.1.el6.i686/weak-updates/video4linux/radio-sf16fmr2.ko 
needs unknown symbol snd_tea575x_init
# Done.
#
# WORKAROUND: just ignore these messages, other modules should work fine.
#
# COMPLETE SOLUTION: none at this moment.
#
#

Yes, this happens. It's what you get when you try to backport large 
numbers of modules that depend on symbols provided by other modules. 
It's not ideal and has the potential to break other modules but these 
large multi-module packages such as alsa, video4linux etc are designed 
to be a last resort one size fits all solution.

A far better solution is to file a bug upstream with Red Hat and get the 
driver you need updated/backported directly into the RHEL kernel. Either 
that, or look to backport only the driver(s) you need. Obviously we 
can't do that for every individual driver in alsa or video4linux hence 
why we go with the sledgehammer approach of packaging the whole bundle.


==============================================================================================================
#
# 3. probably kmod-alsa 1.0.25 should be installed before building 
kmod-video4linux package,
#    and kmod-video4linux also should be installed before building 
kmod-alsa.
#
#    ( not tested/verified right now, this is just supposition )
#
#

No, that's not going to work. You would need to compile the modules 
together if they each depend on symbols provided by the other - just 
installing the package into the build root isn't sufficient to satisfy 
the module dependency. For an example, look at how we build the asus-wmi 
package that depends on symbols provided by the sparse-keymap package.