[linux-dvb] Re: [PATCHES] Frontend kernel i2c conversion.

[Johannes Stezenbach <js@convergence.de>]

On Sun, Jul 18, 2004 at 01:04:02AM +0200, Kenneth Aafløy wrote:
> On Sunday 18 July 2004 00:09, Ralph Metzler wrote:
> > No, I also considered this before implementing the FE_(UN)REGISTER
> > stuff but adapters with more than one I2C bus/frontend will not work like
> > this. It also makes the frontend driver and dvbdev depend on I2C
> > driver structs even if you are not using I2C.
> 
> Hmm, there is no drivers in CVS which has more than one I2C bus, is there?

It is very common for STB chips to have more than one I2C controller -- which
doesn't mean that all I2C buses are used to connect DVB frontends, but it
is not unexpected for a dual-FE box to have each FE on its own I2C bus.

> > Hmm, actually, forget about the last paragraph. There are even more
> > problems, e.g. with the order of module loading, if the dvb_adapter
> > is registered after the I2C bus (like with the bt878 cards).
> 
> I've split up the dvb_register_frontend in this version, because like you, I 
> realized that the previous patch would not even work. This new version works 
> as expected wether or not the dvb adapter has been registered when the i2c 
> bus is up and running. I have had no opportunity to test the bttv driver, but 
> it should work with the converted frontend now.

Something's wrong with your patchset. In dvb-bt8xx.c you *added*
the client_register() functions (unused), while you removed them
everywhere else. Also, IIRC the skystar2 I2C stuff is a bit special
and will fail for general use (that's why the funny checks in
master_xfer() are there).

Johannes