On Fr, 2015-04-24 at 13:53 +0800, Raymond Yau wrote: > Pin complex 0x12 is directly connected to audio input 0x11. > Driver switch between audio inputs node 0x11 and node 0x08 for > The driver need to bind the amp in of node 0x11 and 0x08 to create the > capture volume control when two Mic jacks connected to audio input n > ode 0x08 through node 0x23 internal mic jack and external Mic jack You are right. Forgive me being a bit slow, I haven't looked deeply into mixers before I encountered this problem. Interestingly, the Amps have different characteristics. 0x08 (jack+dock): Amp-In caps: ofs=0x17, nsteps=0x1f, stepsize=0x05, mute=1 0x11 (internal): Amp-In caps: ofs=0x17, nsteps=0x3f, stepsize=0x02, mute=1 However the driver seems to hide this complexity. For simplicity, we should focus the discussion on the jack mics and leave "Internal Mic" aside. I can only say that from user land, volume control of "Internal Mic" apparently behaved the same as the other two Mics. > > > If the described effect occurs, I can see with alsamixer that the > real > > volume is jumping up and down. The volume displayed by "pactl list > > sources" (and likewise by the sliders e.g. in the GNOME volume > control > > widget) is not the real but the user-set value. > > alsamixer -D pulse What's the point? This yields the same values as "pactl list sources", which are wrong, as I showed in my previous mail. > > Here is how PA, Capture, and Boost volume, in dB, correlate in the > error > > case (i.e. if "Capture" is listed before the relevant "Mic Boost" in > the > > path conf file, the current PA default). PA volumes are obtained > using > > "pactl list sources", Capture/Boost values using "amixer -c1 get > > <scontrol>": > > > > PA(%) PA(dB) Captu Boost Capture+Boost-66dB > > 121% 5.00 30.00 36.00 0.000000 > > 100% 0.00 30.00 24.00 -12.000000 > > > > > > > In contrast, if I list "Mic Boost" before "Capture" in the path conf > > file, it looks like this: > > PA(%) PA(dB) Captu Boost Capture+Boost-dB > > 121% 5.00 30.00 36.00 0.000000 > > 100% 0.00 29.25 36.00 -0.750000 > > If base volume is -66dB , why maximum volume and boost is 121%? > Seem total hardware gain exceed pulseaudio limit on maximum gain Sorry for causing confusion. I had observed that setting "0dB" or "100%" in PA didn't actually set full HW volume (actual volume was -12dB or -0.75 dB, see above). So I let my test script move beyond 100%, and because my it made 5dB steps, this has set +5dB/121%. I might as well just set 100.01% in PA. I seems to be necessary to go slightly beyond 100% in PA in order to reach the actual maximum (+30dB Capture and +36dB Boost). That may be a rounding problem. It's not relevant to my point here (well, some may argue that getting -12dB when you set 100% volume is unexpected, but that's a minor issue for me). Coming back to the original point, wouldn't you agree that the way these volume controls behave by default is erratic & confusing? Martin
