Problem being addressed: shell one$ aplay -Dhw:<usbcard> file.wav shell two$ echo mem > /sys/power/state After resume, aplay attempts resume, then restart, then after a timeout gets a write error and no audio will be played until it is restarted.
During suspend/resume, if the USB port remains powered the audio device will still be present upon resume. The interface and endpoint have to be reconfigured however. These patches move the configuration from hw_params to prepare causing re-configuration during resume.
Is this the right way to fix this? Or is there an easier way I am missing?
Thanks for looking.
Dylan Reid (3): ALSA: usb-audio: set period_bytes in substream. ALSA: usb-audio: Don't require hw_params in endpoint. ALSA: usb-audio: Move configuration to prepare.
sound/usb/card.h | 2 + sound/usb/endpoint.c | 29 +++++++----- sound/usb/endpoint.h | 5 ++- sound/usb/pcm.c | 121 +++++++++++++++++++++++++++++++-------------------- 4 files changed, 97 insertions(+), 60 deletions(-)