Hi,
Am 14.08.2012 14:05, schrieb Manu Abraham:
My other device, a STB0899, always reports the set frequency. So it seems
driver dependent whether it reports the actually locked frequency found by
the zig-zag-algorithm or just the set frequency to tune to.
The STV0299 blindly sets the value based on a software zigzag (due to simpler
hardware), but this might not be accurate enough. On the other hand, the
STB0899 internally does zig-zag in hardware for DVB-S2, and partly in
software for DVB-S.
In any event, the get_frontend callback should return the value that is read
from the demodulator registers, rather than the cached original value that
which was requested to be tuned.
The stb0899 returns only the cached value IIRC. Maybe I will fix this soon,
or maybe you can send a patch.
See the attached patch.
This is what I get after the patch:
Sat. Pol. Band Freq (MHz) Set Freq (MHz) Get Delta (MHz)
S19,2E H L 10744 10748,474 4,474
S19,2E H L 10773 10777,944 4,944
S19,2E H L 10832 10836,953 4,953
S19,2E H L 10861 10868,774 7,774
S19,2E H L 10920 10924,312 4,312
S19,2E H L 11023 11026,827 3,827
S19,2E H L 11170 11175,423 5,423
S19,2E H L 11243 11248,452 5,452
S19,2E H L 11302 11307,371 5,371
S19,2E H L 11361 11366,427 5,427
S19,2E H L 11420 11425,473 5,473
S19,2E H L 11464 11468,876 4,876
S19,2E H L 11493 11498,421 5,421
S19,2E H L 11523 11529,080 6,080
S19,2E H L 11582 11586,942 4,942
S19,2E H L 11611 11618,785 7,785
S19,2E H L 11641 11645,951 4,951
S19,2E H L 11670 11675,450 5,450
S19,2E H H 11719 11724,970 5,970
S19,2E H H 11758 11763,975 5,975
S19,2E H H 11797 11802,978 5,978
S19,2E H H 11836 11841,972 5,972
S19,2E H H 11875 11880,951 5,951
I'll have to let VDR "travel" across the transponders several
times to see whether I get similar results for the previously
mentioned transponder on the stv0299 device.
Bye.
--
Dipl.-Inform. (FH) Reinhard Nissl
mailto:[email protected]
--- /usr/src/linux-3.1.10-1.16/drivers/media/dvb/frontends/stb0899_drv.c 2012-08-14 21:59:59.000000000 +0200
+++ stb0899_drv.c 2012-08-14 21:29:17.000000000 +0200
@@ -1596,6 +1596,7 @@ static int stb0899_get_frontend(struct d
dprintk(state->verbose, FE_DEBUG, 1, "Get params");
p->u.qpsk.symbol_rate = internal->srate;
+ p->frequency = internal->freq;
return 0;
}
