sound: usb: Ensure proper cleanup of uaudio_dev under all scenarios
Consider a case where chip is freed before disabling the audio
channel. This can happen when usb_audio_disconnect is called due
to USB DevFS proc_disconnect_claim ioctl. usb_audio_disconnect
will call uaudio_disconnect_cb which will wait for in_use to be
false to cleanup the uaudio_dev. If in_use never becomes false
and the wait_event is interrupted by some other signal then driver
bails out esrly from here and doesn't cleanup the uaudio_dev. Since
uaudio_dev_release is responsible for clearing the in_use based on
stream disable call, fix the cyclic dependency here on
uaudio_dev_release and uaudio_dev_cleanup by adding timeout in
wait_event and allowing dev_cleanup to happen from uaudio_disconnect_cb.
If disable stream request comes after this, handle_uaudio_stream_req
will still go ahead and try to find substream of the card but will
go to error path since card is already disconnected. This will set
the return value to -ENODEV but in the error path driver is not
checking for the correct return value and trying to access chip again.
Fix this by adding one more check for -ENODEV in the error handling path.
Change-Id: Ie11ad162f02c46878eb2663bf21cbafa54a62b0a
Signed-off-by: Pratham Pratap <prathampratap@codeaurora.org>
1 file changed