On 8/8/07, Oliver Endriss <o.endriss@xxxxxx> wrote: > Manu Abraham wrote: > > On 8/6/07, Michael Krufky <mkrufky@xxxxxxxxxxx> wrote: > > > > > > Now I'm beginning to have doubts about Oliver's original patch: > > > > > > dvb_frontend: Range check of frequency and symbol rate > > > http://linuxtv.org/hg/v4l-dvb/rev/8186a34dd0a6 > > > > > > Should we be checking fe->ops.tuner_ops.info.frequency_min|max , instead of > > > fe->ops.info.frequency_min|max ??? > > > > > > Ideally, what's provided by the demod and not the tuner max/min. The > > tuners max/min should be checked by the demod on setting params. > > > > The upper/lower limits in the demodulator drivers, came from the > > concept of a frontend as a whole. Independant bounds do not make sense > > (except internally -- It is the demod driver that which sets > > parameters for the tuner. The external world doesn't need to know > > what's the limit of the tuner, but only of the frontend as a whole). > > > > Ideally, the demodulator should just demodulate only. There are some > > cases, there are some cases which are not. > > Ok, I'm trying to put all pieces together: > There might be cases where demod and tuner have different limits. > > So FE_GET_INFO and dvb_frontend_check_parameters() should use the > 'smallest common bandwidth': > > freq_min = max(fe->ops.info.frequency_min, fe->ops.tuner_ops.info.frequency_min); > > if (fe->ops.info.frequency_max == 0) > freq_max = fe->ops.tuner_ops.info.frequency_max; > else if (fe->ops.tuner_ops.info.frequency_max == 0) > freq_max = fe->ops.info.frequency_max; > else > freq_max = min(fe->ops.info.frequency_max, fe->ops.tuner_ops.info.frequency_max); > > if (freq_min == 0 || freq_max == 0) > printk(KERN_WARNING "frequency limits undefined - please fix the driver\n"); > > Conclusions: > - A tuner-only driver must set fe->ops.tuner_ops.info. > - Monolithic drivers must set fe->ops.tuner_ops.info or fe->ops.info > (or both). > > Ok? Currently, with our status that's the best we can do. Probably, we can hope to have better drivers in the future. Regards, manu _______________________________________________ linux-dvb mailing list linux-dvb@xxxxxxxxxxx http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
