Reinhard Nissl wrote: > when VDR switches to a different transponder the device driver is sent > the above two ioctl()s with appropriate data. > > Just in case the multiswitch get's a damaged DiSEqC message, it won't > choose for example a different polarisation and VDR won't ever get the > expected signal without tuning again. > > I've patched VDR to repeat the DiSEqC message every 500 ms after > FE_SET_FRONTEND until the device's tuner reports LOCKED. An oszilloscope > shows me that the message get's sent on the cable about every 568 ms so > the code seems to be correct. Hm - it should be enough to send the message 2 or 3 times using diseqc.conf. If this does not work there is a severe problem. > But for any reason, the tuning doesn't succeed. I've further added a > timeout of 3000 ms after which FE_SET_FRONTEND is issued again, which > typically tunes successfully then. > > So, it seems that I'm wrong with my assumption that the device keeps on > tuning for at least 2000 ms (BTW: I've never seen the flag TIMEOUT while > tuning) and that repeating the DiSEqC messages should lead to successful > tuning. > > Is it therefore necessary to repeat FE_SET_FRONTEND too at an interval > of 500 ms? > > Would it be ok to shorten the time further (e. g. 300 ms) without > messing up FE_SET_FRONTEND's design (i. e. the current tuning operation > is aborted and a new one is triggered)? > > Is it likely that retuning that fast turns out to be bad on DVB-T or > DVB-C systems? If the first tuning attempt failes the frontend thread starts zip-zag scan. It will take some time until the center frequency is tried again. For details see dvb_frontend.c. > BTW: I'm using DVB-S (NOVA-S), dvb-kernel CVS snapshot of March 2005. Hm - which Nova exactly? Sub-system type from 'lspci -vn' output? The bit-banging diseqc implementation in budget.c cannot work in a reliable way. Interrupts or preemption will distort the diseqc message. Disabling interrupts would probably fix this but imho it is not acceptable to disable interrupts for 54ms! Recently I noticed that problem with an old 13c2:1003 Nova. For my card I have a perfect solution but I'm not sure whether it will work for all Novas with BSRU6 tuner. Oliver -- -------------------------------------------------------- VDR Remote Plugin available at http://www.escape-edv.de/endriss/vdr/ --------------------------------------------------------
