On 07.09.2012 19:57, louis@museresearch.com wrote:
Hi Daniel, Thanks for the quick reply. I am able to set the clock on my Mac, though I do need to do further tests and make sure that the sync is actually reliable there. The setting is available from the built-in, standard OS X audio setup application "Audio MIDI Setup".
There should be a S/PDIF clock signal going to the digital inputs on the device. Some of the other controls such as per-channel mute also appear to work. I've also attached the lsusb output.
There are some other details that may be relevant, but I didn't want to make my initial post too long/confusing because these extra details may end up just being a red herring: Each mixer element name (as seen in amixer) is prefixed with "AudioBox 1818 VSL Clock Selector" even if it is not a clock selector.
That strange but I believe not related. We should still fix that :)
I am confident though that the control I've been playing with is the clock selector because it lists the different clock types as options. I also see this when I plug the device in or load the ALSA driver:
ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue = 0x201, wIndex = 0xa00, type = 4 ALSA sound/usb/mixer.c:846 10:0: cannot get min/max values for control 2 (id 10) ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue = 0x200, wIndex = 0xa00, type = 4 ALSA sound/usb/mixer.c:846 10:0: cannot get min/max values for control 2 (id 10) ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue = 0x201, wIndex = 0xb00, type = 4 ALSA sound/usb/mixer.c:846 11:0: cannot get min/max values for control 2 (id 11) ALSA sound/usb/mixer.c:342 cannot get ctl value: req = 0x83, wValue = 0x200, wIndex = 0xb00, type = 4 ALSA sound/usb/mixer.c:846 11:0: cannot get min/max values for control 2 (id 11)
Do you see any messages when you try to set the clock selector with amixer?
If you're running a recent kernel, try the following patch. That will produce log messages for each mixer related control packet that is sent out to the device.
Thanks, Daniel