[vdr] Re: final solution to the signalless operation problemfound!! -> testers+RFC required

[a.share@t-online.de (Andreas Share)]

> Am Wednesday 24 March 2004 21:22 schrieb Klaus Schmidinger:
> > I don't see why VDR should be the culprit here.
> > What's wrong with opening the frontend and not actually using it?
> > Shouldn't the driver (or whoever is responsible) be stable enough
> > to handle this?
> >
> > Of course we can add an option that makes VDR not open the frontend
> > in case the user knows that there is no antenna cable connected - but
> > that still leaves the case where the signal gets lost for other reasons.
> > And then what happens if the user forgets to set that option?
>
> Just to state it correctly here - my current analysis shows vdr _needs_ to
> open the frontend and call  -if proposed option is set - FE_SLEEP
instantly.
>
> Not opening the device at all (including Andreas' patch) did not have the
> stabilizing effect.
>
> > After all, your computer doesn't crash just because a program opens
> > a file and then doesn't read from it... ;-)
>
> Exactly - i suppose, that in case the frontend runs without or with bad
signal
> one of the following cases produces the problem:
> 1.the chip outputs blocks with IEI-Bit not set but erronous data
> 2.the frontend generates a lot of (unwanted) interrupts if no/bad signal,
> confusing the ARM
> 3.the ARM get's correctly informed by IEI-Bit but fails in correct
handling of
> uncorrect blocks
> 4.by chance the frontend "correctly" generates correct blocks out of the
noise
> which are actually just noise no data -> confusing the ARM
>
> cases 1,2 assume a hardware implementation error, cases 3 or 4 a potential
> weakness in the firmware. Unfortunately one can only decide what is
happening
> with a logic analyser connected to the data-path between the 2 chips.

Hi,

this is only an workaround for use without signal...because you can´t do
anything against bad weather conditions or some other things causes a less
good signal the ARM (firmware) *must* never crashed under this conditions.
And, so many other receivers around use the the frontend and tuner, without
such problems.

Because the older driver works much more solid under this conditions, only
3+4 could cause the problems.

Andreas




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