[linux-dvb] Re: cinergyT2: which kernel/usb module to use?

[Holger Waechtler <holger@qanu.de>]

Ralph Metzler wrote:

> Johannes Stezenbach writes:
> > Stefan Lucke wrote:
> > > The bad thing is, that with vdr (1.3.7) I had a system freeze again (caps
> > > lock and scroll lock continuously on).
> > 
> > I already reported that there is an infinite recursion in
> > Holger's FE_GET_EVENT implementation. You'll just get
> > a stack overflow.
> > 
> > The whole issue could be trivially fixed by converting cinergyT2
> > to use the dvb_frontend core, as *all* other frontends do.
> > I would volunteer to do that, however I won't unless Holger
> > gives me an OK -- I guess he had some reasons not to use
> > dvb_frontend.
>
>
> I don't know his reasons but for some frontends you just do 
> not need/want the whole dvb_frontend stuff, especially if it 
> is changing every few weeks.
> I am also not using it for Twinhan cards myself.
> Maybe dvb_frontend should just export some message queue handling
> calls. 
>  
It would be nice if all subsystems and infrastructure code would get 
converted slowly to a library-alike interface so that it is possible to 
use only parts of it without being forced to give full control to the 
infrastructure support code.

I want to use the cinergyT2 driver as testbed for the v5 mmap() 
experiments and thus need full access to the frontend fops, this was the 
primary reason to bypass the dvb_frontend code.

Modern hardware doesn't needs anything the dvb_frontend code provides, 
most of the code there are fallbacks and workarounds for ancient 
demods+PLLs.

> Regardless of all this, an application should handle getting an
> EINVAL or ENOTSUPP from FE_GET_EVENT.
>  
right.

Holger