25 Mar
2018
25 Mar
'18
5:32 a.m.
Hi Guys,
Running jack with a small buffer (-p64 -n2), and connecting with any
client causes issues.
With higher buffer sizes, all is OK.
This is on an ARM embedded system, with a single core 1MHz processor.
I've set the cpu governor to performance.
I have a custom compiled 4.14 kernel with omap2plus_defconfig with the
following config settings:
CONFIG_PREEMPT_VOLUNTARY=y
HZ_100=y
CONFIG_NO_HZ_IDLE=y
$ jackd -R -P95 -dalsa -dhw:0 -r48000 -p64 -n2
JackPosixProcessSync::LockedTimedWait error usec =
5000000 err = Connection timed out
Driver is not running
Cannot create new client
CheckSize error size = 32 Size() = 12
CheckRead error
CheckSize error size = -1 Size() = 4
CheckRead error
CheckSize error size = 0 Size() = 12
CheckRead error
Also, with higher buffer sizes sometimes I get xruns. After enabling
alsa debugging, the error is:
ALSA: PCM: [Q] Lost interrupts?: (stream=0, delta=221,
new_hw_ptr=181343, old_hw_ptr=181122)
Loosing the FIFO interrupts doesn't seem like a great thing.........
I _think_ the issue is to do with the kernel scheduling, but this why
I ask the experts :-).
Can anyone suggest any kernel settings that will improve my situation?
Many thanks,
Chris