[linux-dvb] Re: Erroneous unsupported PLL synthesizer: foundit!!

[Holger Waechtler <holger@convergence.de>]

Andrew de Quincey wrote:
> On Monday 17 March 2003 10:41, Holger Waechtler wrote:
>
> > Andrew de Quincey wrote:
> >
> > > On Friday 14 March 2003 18:35, Ralph Metzler wrote:
> > >
> > > > Andrew de Quincey writes:
> > > >
> > > > > Hi, I've found the problem. It seems to be the same one as mentioned
> > > > > in "dvb-kernel and alps_bsru6 not tuning" from Matt Davis on Mon, 03
> > > > > Feb 2003.
> > > > >
> > > > > Basically, sending both i2c commands at the same time means the
> > > > > stv0299 bus repeater does not have enough time (the i2c device returns
> > > > > BUSY 'cos it hasn't finished with the first message). Adopting the
> > > > > same solution (breaking all the double-i2c PLL writes up into two
> > > > > single ones) makes the PLL work again.
> > > > Well, I did ask you yesterday if PLL writes are done in one transfer
> > > > or two in the driver you are using.
> > > Yeah, I wasn't quite sure what you meant. In hindsight, of course, it all
> > > makes sense now :)
> > >
> > > Anyway, shall I just patch it in for my PLL chip in particular, or just
> > > change all the PLL code to use seperate i2c transmissions?
> > No. The right fix for this problem is to insert real delays (preferably
> > ddelay() calls of the average length of one or two i2c messages) in the
> > retry loop in the saa-i2c driver. Otherwise you'll get into these
> > problems again when you buy your next, faster PC.
> >
> > Would you be willing to implement this and send a patch?
>
> One thing; at the moment the SAA i2c code specifically does not retry if it 
> gets an address error.. so in this case, there are never any retries because 
> it gets an address error. I'd have to remove this check to implement your 
> suggestion. Is this OK?
yes.

Holger



--
Info:
To unsubscribe send a mail to listar@linuxtv.org with "unsubscribe linux-dvb" as subject.