On Wed, Aug 5, 2009 at 1:16 PM, Jon Smirl<jonsmirl@xxxxxxxxx> wrote: > 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. My hardware engineer has this one, but it is in Seattle and I am in Florida. The OpenMoko guys use it. http://www.pctestinstruments.com/ You can write your own interpreters, someone may have done AC97 for it but I haven't checked. He also has a Rigol DS1102E which he says is an awesome scope for $636. Another tip from OpenMoku. http://www.tequipment.net/RigolDS1102E.html -- Jon Smirl jonsmirl@xxxxxxxxx _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
