On Thursday 09 June 2005 00:08, Andrew de Quincey wrote: > On Wednesday 08 June 2005 23:04, Andrew de Quincey wrote: > > > Incidentally, my latest test was to set the tone every 60 seconds in > > > the frontend loop. This didn't work though - it still lost the lock, > > > and went into the patch I posted earlier and regained it simply by > > > setting the tone. > > > > My mistake - there was a bug in this code which meant it wasn't actually > > doing the above. I've corrected it and am waiting to see if it still > > loses the lock. > > Nope - its just lost it and ran the auto-regain-by-setting-tone code. > > So to summarise my current findings: > *) Setting the tone every 60 seconds does not help. > *) Setting the tone when the lock is lost causes it to be regained in under > 100ms. > *) If you don't set the tone/reg0x08 on lock loss, you will never regain > the lock. > *) The contents of register 0x08 of the stv0299 stay constant. > *) It cannot be noise/traffic on the i2c bus changing other registers since > the only thing needed to fix the issue is to set register 0x08 again. > *) No i2c traffic to the stv0299 besides reading the lock status occurs > after the initial tuning attempt. > *) Only a few cards are affected. Cards tuned to the same channels on other > sites are fine. Cards using the same multiswitch at the same site are fine. > *) At a site with the issue, channels can be manually reassigned between > cards/machines until a stable situation is found. This is very time > consuming though. > *) Temperature is unlikely to be a cause. > *) This problem occurs across a whole range of stv0299 based cards (we have > several vintages of them from the last few years). > *) There is no pattern temporally to the lock loss. > *) The problem occurs across different multiswitches by different > manufacturers. > *) The signal is perfect (BER==0) up until the time the lock is lost. > *) The problem _may_ affect stv0299 based Twinhan cards as well, but this > needs verified. Another one: *) It is not interference from other DVB cards in the same machine - the machine I am testing stuff on only has one DVB-S card in it (and it doesn't have any DVB-T cards in it either).
