[alsa-devel] [PATCH v2 0/6] Propagate errors out from compressed streams

[Charles Keepax]

If the DSP suffers an unrecoverable error, the driver likely
knows about this, however the framework may not get informed
because errors returned from pointer requests are ignored within
the framework.

Things work out fine if user-space is doing a read as reads
return error status back to user-space so the user can find out
that things have gone bad. However, if user-space is doing an
avail request there is no path for the error to come back up to
user-space. The pointer request returns zero available data, so a
read never happens and we basically just end up sitting waiting
for data on a stream that we know full well has died.

This patch set attempts to address this and ensure that errors
are fully propagated to user-space and we don't ever end up wait
for data that will never come.

Changes since v1:
 - Based on a recommendation from Vinod, rather than handling
   errors from pointer requests, add a new call that allows us to
   inform the compress core that the stream has gone bad. Then
   return errors from the avail and poll callbacks if the stream is
   bad.

Thanks,
Charles

Charles Keepax (6):
  ASoC: compress: Pass error out of soc_compr_pointer
  ALSA: compress: Add function to indicate the stream has gone bad
  ALSA: compress: Replace complex if statement with switch
  ASoC: wm_adsp: Factor out fetching of stream errors from the DSP
  ASoC: wm_adsp: Improve DSP error handling
  ASoC: wm_adsp: Use new snd_compr_stop_xrun to signal stream failure

 include/sound/compress_driver.h |  3 ++
 sound/core/compress_offload.c   | 67 ++++++++++++++++++++++++++++++++++++++---
 sound/soc/codecs/wm_adsp.c      | 43 +++++++++++++++++++-------
 sound/soc/soc-compress.c        |  5 +--
 4 files changed, 101 insertions(+), 17 deletions(-)

-- 
2.1.4