[mythtv-users] Where do I find documentation on these modules?

Nick Rout nick.rout at gmail.com
Tue May 4 07:49:01 UTC 2010

On Tue, May 4, 2010 at 12:40 PM, Douglas Peale
<Douglas_Peale at comcast.net> wrote:
> Hash: SHA1
> On 05/02/2010 02:11 PM, Douglas Peale wrote:
>> I'm looking for documentation on the following modules:
>> cx8800
>> cx88Sdvb
>> nxt200x
>> cx88_alsa
>> tuner
>> tuner_simple
>> tuner_types
>> tda9887
>> tda8290
>> I have a script from Harry Orenstein that messes with these, and gets the analog tuner to sort of work, but I don't know what the script is doing.
>> (it uses options that are not documented with modprobe)
>> At the moment, it allows me to scan for channels, but viewing liveTV with the analog tuner, I get about 1 second of video before the
>> picture freezes, goes black and/or starts flikering garbage every time I start viewing, or change channel.
> After a bunch of googling, I happened on a thread that mentioned "modinfo"
> With that, I can at least get a listing of options for the modules. Unfortunately, it does not explain what the options do.
> For example
> $ modinfo cx88_alsa
> filename:       /lib/modules/2.6.32-22-generic/kernel/drivers/media/video/cx88/cx88-alsa.ko
> license:        GPL
> author:         Mauro Carvalho Chehab <mchehab at infradead.org>
> author:         Ricardo Cerqueira
> description:    ALSA driver module for cx2388x based TV cards
> srcversion:     F9E11ADA4E7D84EB0B44F96
> alias:          pci:v000014F1d00008811sv*sd*bc*sc*i*
> alias:          pci:v000014F1d00008801sv*sd*bc*sc*i*
> depends:        videobuf-dma-sg,cx88xx,snd-pcm,snd,btcx-risc
> vermagic:       2.6.32-22-generic SMP mod_unload modversions
> parm:           enable:Enable cx88x soundcard. default enabled. (array of bool)
> parm:           index:Index value for cx88x capture interface(s). (array of int)
> parm:           debug:enable debug messages (int)
> index: Index value for cx88x capture interface(s). (array of int)
> tells me I can set index to an array of ints, and that they are index values for cx88x capture interface(s),
> but I have no idea what an index value for cx88x capture interface(s) are.
> Where can I find out?

I am only semi facetious in saying that the code is the documentation!

I have found over the years, particularly when using gentoo because it
makes you get dirty, that modules start life as some out of kernel
addon, and get quite well documented. Then they get added into the
kernel proper, and the documentation disappears, or appears in
shortened form, in the Documentation directory of the kernel source.
Also bleeding edge development might still occur outside the kernel
tree, to be merged at random intervals, and without knowing for sure
what SVN version is in what kernel. Whats more binary dsistros don't
automatically include the kernel spurce, so the docos that are in
there, but not in the compiled kernel, are not on your system.

In short, browse the Documentation directory of your kernel source, or
for specialised modules like the ones you refer to join the linux-tv
mailing list (or search it)

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