On Wed, Aug 05, 2009 at 09:30:53AM -0700, John Bonesio wrote: > I've retitled the email to better reflect the real patch. I believe > there has been some general confusion because I originally sent the > wrong patch. Retitling again; I don't think we've diagnosed what is causing issues here. Doing a quick test here I wasn't able to reproduce this behaviour so I suspect either the AC97 controller by itself or some interaction between it and the WM9712. Like I say, the WM9712 is not a new part and the drivers aren't new either so it'd be surprising to find an issue like this now. > > Like I said before, exactly which control are you adjusting here? > My description of this got lost in all the confusion. Let me try again. > We are adjusting the mixer bits for mute/unmute on two of the mixer > settings. The first one is general headphone mute setting on register > 0x4 (bit 15). The second one is the PCM mute setting on register 0x18 > (bit 15). Hrm, so the same bit in both registers. Suspicious... > What we are seeing is that if we first unmute the general headphone (reg > 0x4 bit15), then unmute the PCM (reg 0x18 bit 15) [HPL PCM in the > alsamixer application], the general headphone gets muted again, even > though software didn't write to that register. Are any other bits in register 4 affected or is it only bit 15? > > My money would be on the AC97 controller having problems; the quality of > > SoC AC97 controllers is variable. It certainly doesn't sound like a > > WM9712 issue; as I say I'd be very surprised if such an issue hadn't > > come up before given how widely deployed the part is. > We don't have access to an AC97 analyzer. Do you have any suggestions on > other ways we can pinpoint the error? Any scope that can capture would be useful to see what's going on; obviously decode would have to be by hand. Coding out the register cache may also be useful - it'd allow you to see the current hardware register values. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
