[linux-dvb] Re: refactoring

[Holger Waechtler <holger@qanu.de>]

Gerd Knorr wrote:

> > > Have stuff visible in sysfs, firmware loads, powermanagement
> > > (suspend/resume), make the code easier to read for others by using
> > > the usual structures rather than inventing your own, ...
> > >      
> > Frontend devices are already visible through sysfs, check dvbdev.c.
> >    
> Not in /sys/devices, which is needed for powermanagement, because the
> power management code walks the device tree on suspend/resume.
>  
Power management is transparently handled by the card driver, both the 
USB and PCI hooks have suspend/resume callbacks which put the frontend 
asleep or wake it up and reinitialize it. Even an open/close() will 
power down the LNB, switch and demod in the current architecture if they 
are not used.

Problematic is only DiSEqC: Since this protocol is stateless the 
application needs to re-send the DiSEqC sequence completely (that's 
where the FE_REINIT status flag in the frontend API was intended for. is 
this actually correctly implemented by any driver+application out there? 
but this is in any case a general problem which will show up no matter 
which approach is used for power management).

Holger