On Wed, Aug 5, 2009 at 12:30 PM, John Bonesio<bones@xxxxxxxxxxxx> wrote: > Hi Mark, > > 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. > > You wrote: > >> 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). > > 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. > >> >> > If there is code in software doing this, it's very subtle. >> >> 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? Do you have a normal logic analyzer? You can decode the AC97 by hand, its only a couple of frames. -- Jon Smirl jonsmirl@xxxxxxxxx _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
