On Mon, Jan 16, 2017 at 9:17 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170113 21:16]:
On Fri, Jan 13, 2017 at 7:20 AM, Tony Lindgren tony@atomide.com wrote:
- Matt Ranostay matt@ranostay.consulting [170112 19:55]:
We can get audio errors if hitting deeper idle states on omaps:
[alsa.c:230] error: Fatal problem with alsa output, error -5. [audio.c:614] error: Error in writing audio (Input/output error?)!
This seems to happen with off mode idle enabled as power for the whole SoC may get cut off between filling the McBSP fifo using DMA. While active DMA blocks deeper idle states in hardware, McBSP activity does not seem to do so.
Basing the QoS latency calculation on the FIFO size, threshold, sample rate, and channels.
Based on the original patch by Tony Lindgren Link: https://patchwork.kernel.org/patch/9305867/
Cc: Tony Lindgren tony@atomide.com Cc: Peter Ujfalusi peter.ujfalusi@ti.com Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com Signed-off-by: Matt Ranostay matt@ranostay.consulting
Changes from v1:
- add calculations for latency per number of FIFO locations
Changes from v2:
- add missing mcbsp.h header change
Changes from v3:
- base the latency calculations on threshold, buffer size, sample rate, and channels
Changes from v4:
- using Peter Ujfalusi's suggestions for restoring a higher latency on audio stream completion, or if not applicable remove the QoS request
Changes from v5:
- clean up latency checking logic
- move logic to .prepare and .shutdown to avoid functions that can sleep
Changes from v6:
- move QoS removal to asoc_mcbsp_remove from omap_mcbsp_cleanup
- also remove header include that is unneeded
Hmm now I'm seeing these when starting or stopping playback:
Ok I can't reproduce but I have an idea why it is happening. There is likely a race condition between pm_qos_remove_request() and omap_mcbsp_dai_shutdown()... Should we do a pm_qos_request_active check in omap_mcbsp_dai_shutdown? That seems to be hacking around the issue.
OK. Again this is with next using omap2plus_defconfig and:
CONFIG_DEBUG_LOCKDEP=y CONFIG_DEBUG_ATOMIC_SLEEP=y
Yep I was testing with that enabled. Not sure why I'm not getting it all... maybe different side effects like sample rate of the audio being played?
Peter, is there chance that there is race condition is possible between pm_qos_remove_request and omap_mcbsp_dai_shutdown?
Regards,
Tony