drmatt wrote: > Based on what OS, kernel, and software stack? > > The udev system should handle initialisation of the DAC if it's plugged > in post boot. You should at least see a kernel log message when the DAC > joins the USB bus, even if no driver subsequently loads to manage it.
Armbian os (xenial) with logsleep (allwinner) kernel 3.10.104 (the only viable kernel for the pine64 soc device at the moment). Having posted, I can't reproduce the second scenario now, so please forget that for the moment. The white noise is still present though, as soon as alsa loads. Stack would probably be something like: 1. ehci: Code: -------------------- dmesg: [ 3092.731854] ehci_irq: highspeed device connect [ 3092.953708] usb 2-1: new high-speed USB device number 2 using sunxi-ehci [ 3093.181941] usbcore: registered new interface driver usbhid [ 3093.181952] usbhid: USB HID core driver [ 3094.710561] input: SMSL AUDIO Sanskrit PRO as /devices/soc.0/1c1b000.ehci1-controller/usb2/2-1/2-1:1.2/input/input6 [ 3094.712441] hid-generic 0003:0D8C:0062.0001: input,hidraw0: USB HID v1.00 Device [SMSL AUDIO Sanskrit PRO] on usb-sunxi-ehci-1/input2 -------------------- 2. ALSA: Code: -------------------- aplay -L null Discard all samples (playback) or generate zero samples (capture) pulse PulseAudio Sound Server default:CARD=PRO Sanskrit PRO, USB Audio Default Audio Device sysdefault:CARD=PRO Sanskrit PRO, USB Audio Default Audio Device front:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio Front speakers surround21:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 2.1 Surround output to Front and Subwoofer speakers surround40:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 4.0 Surround output to Front and Rear speakers surround41:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio IEC958 (S/PDIF) Digital Audio Output dmix:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio Direct sample mixing device dsnoop:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio Direct sample snooping device hw:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio Direct hardware device without any conversions plughw:CARD=PRO,DEV=0 Sanskrit PRO, USB Audio Hardware device with all software conversions -------------------- squeezelite: Code: -------------------- squeezelite-R2 -l Output devices: null - Discard all samples (playback) or generate zero samples (capture) pulse - PulseAudio Sound Server default sysdefault:CARD=PRO - Sanskrit PRO, USB Audio - Default Audio Device front:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Front speakers surround21:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 2.1 Surround output to Front and Subwoofer speakers surround40:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 4.0 Surround output to Front and Rear speakers surround41:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 4.1 Surround output to Front, Rear and Subwoofer speakers surround50:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 5.0 Surround output to Front, Center and Rear speakers surround51:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 5.1 Surround output to Front, Center, Rear and Subwoofer speakers surround71:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - 7.1 Surround output to Front, Center, Side, Rear and Woofer speakers iec958:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - IEC958 (S/PDIF) Digital Audio Output dmix:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Direct sample mixing device dsnoop:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Direct sample snooping device hw:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Direct hardware device without any conversions plughw:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Hardware device with all software conversions -------------------- The default output device for squeezelite is hw:CARD=PRO,DEV=0 - Sanskrit PRO, USB Audio - Direct hardware device without any conversions which obviously causes squeezelite startup to fail when the card is not found. I'm thinking that I should modify the startup script for squeezelite to wait until the hw:CARD=PRO,DEV=0 is present, before starting. Should be a way of doing that, or taking the squeezelite start script out of init and link it to a udev rule ??? But I'm sure that I'm not the first to have the problem, so there's probably a standard solution lying around somewhere, if I can find it. Regarding the white noise, I'm guessing that alsa is initialising the device in the wrong mode somehow. Again: any standard solution that may be missing on my system?? BR. ------------------------------------------------------------------------ Learnincurve's Profile: http://forums.slimdevices.com/member.php?userid=64807 View this thread: http://forums.slimdevices.com/showthread.php?t=107082 _______________________________________________ unix mailing list unix@lists.slimdevices.com http://lists.slimdevices.com/mailman/listinfo/unix