Greetings,

I'm enabling a sink(ETR) via sysfs:

$ echo "1"> /sys/bus/coresight/devices/826000.etr/enable_sink

And the sink is enabled successfully.

Now, i try to turn on a random ETMv4 source, so i just choose this one:

$ echo "1" > /sys/bus/coresight/devices/85c000.etm/enable_source

And this freezes my entire system. This ETMv4 is for CPU 0.. So i tried to turn on(after a reboot, and enabling a sink again) the next ETMv4(for CPU 1):

$ echo "1" > /sys/bus/coresight/devices/85d000.etm/enable_source

And i can see the kernel logs are happy, and tracing is(assuming the logs are true) enabled:

[ 61.495119] coresight-tmc 826000.etr: TMC-ETR enabled
[ 61.495150] coresight-dynamic-replicator 824000.replicator: REPLICATOR enabled
[ 61.499261] coresight-tmc 825000.etf: TMC-ETF enabled
[ 61.506468] coresight-funnel 821000.funnel: FUNNEL inport 4 enabled
[ 61.511438] coresight-funnel 841000.funnel: FUNNEL inport 1 enabled
[ 61.517635] coresight-etm4x 85d000.etm: ETM tracing enabled

But when i try to turn it off:

$ echo "0" > /sys/bus/coresight/devices/85d000.etm/enable_source

This freezes my entire system.. again.

I'm using the perf-opencsd-master kernel(https://github.com/Linaro/perf-opencsd),

and the Dragonboard 410c.

Any ideas, hints?

Thank you.