[alsa-devel] [PATCH v4 00/15] ALSA: usb-audio: fix playback/capture concurrent usage

[Takashi Iwai]

At Sun,  6 Oct 2013 22:31:05 +0200,
Eldad Zack wrote:
> 
> Hi,
> 
> This patch series attempts to fix a long standing problem with the concurrent
> usage of playback and capture on implicit feedback devices.
> 
> Now the following work properly on my system:
> * Full-duplex with jack :)
> 
> * All tests I ran with my tool. Will post it in case anyone want to try it,
>   it takes about 15 minutes to run all the tests.
> 
> * Starting a capture-only jackd instance, e.g.:
>     jackd -n 1 -d alsa -d hw:2,0 -C
>   and then playback-only:
>     jackd -n 2 -d alsa -d hw:2,0 -P
>   and then stop and start the playback.
>   The same with playback running and restarting capture.
> 
> * Trying to start a second substream with parameter mismatch (rate or
>   period bytes is all I can test with my device) will fail,
>   without ill effects.
> 
> With this series applied there are now 3 usage tracking variables:
>  - substream usage flag
>  - endpoint param_set (to protect the parameters until the endpoint is started)
>  - the existing endpoint use_count
> 
> Changes from v3:
> * Added substream "used" flag, to prevent failure in some combinations of ops. (#13)
> * Moved start_endpoints for capture to prepare (#14)
> * Added more constraints to the endpoint_may_set_params function (#10)
> * Cleanups (#12, #15)
> 
> v3:
> http://mailman.alsa-project.org/pipermail/alsa-devel/2013-August/065744.html
> 
> Applies against for-next, tested on upstream 3.12-rc3 (needs Alan Stern's recent
> patch "improve buffer size computations for USB PCM audio" to apply cleanly
> on current mainline).
> 
> Daniel and Nikolay: if you can test again with this series I'd appreciate it.
> 
> Cheers,
> Eldad
> 
> Eldad Zack (15):
>   ALSA: usb-audio: remove unused parameter from sync_ep_set_params
>   ALSA: usb-audio: remove deactivate_endpoints()
>   ALSA: usb-audio: prevent NULL dereference on stop trigger
>   ALSA: usb-audio: don't deactivate URBs on in-use EP
>   ALSA: usb-audio: void return type of snd_usb_endpoint_deactivate()
>   ALSA: usb-audio: clear SUBSTREAM_FLAG_SYNC_EP_STARTED on error
>   ALSA: usb-audio: correct ep use_count semantics (add set_param flag)
>   ALSA: usb-audio: rename alt_idx to altsetting
>   ALSA: usb-audio: conditional interface altsetting
>   ALSA: usb-audio: conditional concurrent usage of endpoint
>   ALSA: usb-audio: remove altset_idx from snd_usb_substream
>   ALSA: usb-audio: remove unused endpoint flag EP_FLAG_ACTIVATED
>   ALSA: usb-audio: clear sync subs hw_params
>   ALSA: usb-audio: always wait in start_endpoints
>   ALSA: usb-audio: improve logging messages

For reducing the further development, I applied trivial cleanup / fix
patches now, namely, below have been merged now:
  ALSA: usb-audio: remove unused parameter from sync_ep_set_params
  ALSA: usb-audio: remove deactivate_endpoints()
  ALSA: usb-audio: don't deactivate URBs on in-use EP
  ALSA: usb-audio: void return type of snd_usb_endpoint_deactivate()
  ALSA: usb-audio: clear SUBSTREAM_FLAG_SYNC_EP_STARTED on error
  ALSA: usb-audio: rename alt_idx to altsetting
  ALSA: usb-audio: remove unused endpoint flag EP_FLAG_ACTIVATED

The patches below need trivial fixes:
  ALSA: usb-audio: prevent NULL dereference on stop trigger
  ALSA: usb-audio: improve logging messages

And these need reconsideration:
  ALSA: usb-audio: always wait in start_endpoints
  ALSA: usb-audio: correct ep use_count semantics (add set_param flag)

I'll check the rest later.


thanks,

Takashi

> 
>  sound/usb/card.h     |   9 ++-
>  sound/usb/endpoint.c | 122 ++++++++++++++++++++---------
>  sound/usb/endpoint.h |  13 +++-
>  sound/usb/pcm.c      | 214 ++++++++++++++++++++++++++++++++++++---------------
>  sound/usb/pcm.h      |   2 +
>  sound/usb/proc.c     |   4 +-
>  6 files changed, 258 insertions(+), 106 deletions(-)
> 
> -- 
> 1.8.1.5
>