[linux-dvb] Re: Is this legal/safe to open a demuxer before opening the frontend ?

[Johannes Stezenbach <js@convergence.de>]

Christophe Thommeret wrote:
> What i'm doing :
> 
> - at program startup (KaxTV), eit reading is started.
> - then, switching channels open/close the frontend.
> - at program stop, eit demux is closed.
> 
> It seems to work in most cases, but for some users :
> 
> - first program start works.
> - then program hangs on restart.
> - reloading drivers sometimes help once, but next restart ends with machine 
> crash.
> 
> Since (x)zap always works, i wonder if this is legal/safe to ....

It should be legal, but it cannot be made failsafe for some hardware :-(

(av7110 may crash if you have a frontend which outputs noise when
not tuned to signal; this is probably a bug in the RTSL or in the
firmware error handling. Anyway, the host should not crash when the
av7110 crashes, this is a bug in the av7110 drivers error handling.
Note that most newer frontends mute their TS output when they cannot
sync to a signal).

To be safe you should 1. tune, 2. wait for FE_GET_EVENT to return
success, 3. set filters. Before tuning, stop all filters.

Johannes