On 01/12/2017 09:35 AM, Matt Ranostay wrote:
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 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
Looks good.
You can add my Acked-by: Peter Ujfalusi peter.ujfalusi@ti.com
to v7...
sound/soc/omap/mcbsp.c | 1 + sound/soc/omap/mcbsp.h | 3 +++ sound/soc/omap/omap-mcbsp.c | 47 ++++++++++++++++++++++++++++++++++++++++++++- 3 files changed, 50 insertions(+), 1 deletion(-)
diff --git a/sound/soc/omap/mcbsp.c b/sound/soc/omap/mcbsp.c index 06fec5699cc8..8fdb949a266e 100644 --- a/sound/soc/omap/mcbsp.c +++ b/sound/soc/omap/mcbsp.c @@ -25,6 +25,7 @@ #include <linux/io.h> #include <linux/slab.h> #include <linux/pm_runtime.h> +#include <linux/pm_qos.h>
Which would not add this include line ;)
#include <linux/platform_data/asoc-ti-mcbsp.h>