Mauro Carvalho Chehab writes: > Em Mon, 26 Jun 2017 10:55:34 +0200 > Ralph Metzler <rjkm@xxxxxxxxxxxxxx> escreveu: > > > Daniel Scheller writes: > > > From: Daniel Scheller <d.scheller@xxxxxxx> > > > > > > Original code at least has some signed/unsigned issues, resulting in > > > values like 32dBm. > > > > I will look into that. > > > > > Change signal strength readout to work without asking > > > the attached tuner, and use a lookup table instead of log calc. Values > > > > How can you determine the exact strength without knowing what the tuner did? > > At least the stv6111 does its own AGC which has to be added. > > I remember I had to solve this issue on some other driver[1][2][3]. What I > did was to get the AGC gain from the tuner using a callback, > then I added it to the main gain. > > [1] https://www.spinics.net/lists/linux-media/msg101836.html > [2] https://www.spinics.net/lists/linux-media/msg101838.html > [3] https://www.spinics.net/lists/linux-media/msg101842.html > > I don't remember why it was not merged upstream, though. Perhaps because > I was in doubt about reporting it as "rf_attenuation" or as "agc gain". > > Anyway, with something like that, any demod could check for such > callback. If defined, add it to its AGC own gain, in order to get > the total AGC gain. I misused get_rf_strength for this in my versions of stv6111.c/stv0910.c. But get_rf_attenuation would be exactly what we need. Daniel now removed the get_rf_strength() call from stv0910.c and ignores the correction from the tuner. That was what I was commenting on. Regards, Ralph
