I have about 20+ Yuns recording audio using a sound card. Every now and then, one particular device stops recording intermittently.
When I try to restart the recording, the ffmpeg encoder fails to detect the USB card and throws an I/O error. Resetting the USB device does not fix the problem. Only power cycle of the device restarts the recording.
When the Yun has stopped recording, I looked into the system messages:
[ 3152.500000] retire_capture_urb: 5000 callbacks suppressed
[ 3157.510000] retire_capture_urb: 5000 callbacks suppressed
[ 3162.520000] retire_capture_urb: 5000 callbacks suppressed
[ 3167.530000] retire_capture_urb: 5000 callbacks suppressed
Since it is happening on the same device, could this attributed to the sound card and not the Yun's USB stack/host controller?
I am using a cheap $7 USB sound card.
yamanoorsai_15:
Since it is happening on the same device, could this attributed to the sound card and not the Yun's USB stack/host controller?
Maybe. The standard test in a situation like this is to swap the sound cards between two Yuns. If the problem still happens on the same Yun, then look into the software, hardware, or storage on that Yun. If the problem now happens on the Yun that got the suspect sound card, you can make a pretty good guess that it's the sound card.
Be aware that due to some polarity protection diodes on the Yun, devices plugged into the USB port don't get a full 5 volts. It may be that your one sound card is susceptible to low voltage. Using a powered USB hub is the typical work-around to make sure the USB devices get the normal full voltage.
Yeah. It happens only on this device. Replacing the cards seem to work only for a couple of hours. I wish there was a way where the USB sound card re-enumerates correctly upon reset. I tried upgrading the OS to Chaos Calmer hoping that it would improve USB stability. No luck.