On Thu, Aug 09, 2012 at 09:33:43AM +0200, Takashi Iwai wrote: > At Thu, 9 Aug 2012 09:18:48 +0200, > Thierry Reding wrote: > > > > On Thu, Aug 09, 2012 at 09:02:10AM +0200, Takashi Iwai wrote: > > > At Thu, 9 Aug 2012 08:47:19 +0200, > > > Thierry Reding wrote: > > > > > > > > Unmuting the analog bypass causes any input to be directly bypassed to > > > > the outputs, which is usually not expected by the user. > > > > > > > > Signed-off-by: Thierry Reding <thierry.red...@avionic-design.de> > > > > --- > > > > Note that this patch could be generalized to include all codec variants > > > > that have this second channel. As I don't have access to all the data > > > > sheets I'll leave that decision up to somebody with more hardware > > > > available. > > > > > > Hmm, are you really sure that this is exclusive switch between two? > > > All Realtek codecs with this mixer widget mixes two sources up. > > > Otherwise it must not be a "mixer" widget at all but it must be a > > > "selector" widget. > > > > It's not an exclusive switch. But the second input is the analog bypass > > that basically takes the signal directly from the input path and routes > > it to the output. > > Ah so you mean it as the analog loopback path.
Yes. > > > And I haven't received a bug report regarding this although ALC892 is > > > no new chip and the auto-parser has been enabled for so long time. > > > > I've seen this happen when feeding a signal into the CD-IN (NID 0x1c), > > which is then directly routed to the output, so I actually hear that > > signal at the output, even if there is no software loopback to capture > > the input and play it back via the DAC. > > > > This is probably not a very common use-case, so maybe nobody else has > > come across it. Looking at the block diagram in the ALC892 datasheet > > (page 5) clearly shows where the input of this second switch comes from. > > I don't think this is intended to be unmuted by default, but only in > > very special cases where you actually want to pass the analog input > > signal directly to the output without going through the ADC and back out > > the DAC. > > Each input has the analog loopback mixer switch (and off as default). > Why it doesn't suffice? I hadn't thought about that. I'll need to recheck if that solves the issue that I was seeing. Thierry
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