Re: [alsa-devel] How to show hda trace events in a self-built kernel?

On 2014-04-23 09:35, Lin, Mengdong wrote:

Hi,

How to show hda trace events in a self-built kernel?

With a self-built kernel under Ubuntu 13.04 or 13.10, I enabled hda trace events by

#cd /sys/kernel/debug/tracing/

#echo 1 > events/hda/enable

#echo 1 > events/had_intel/enable

Then I check the codec proc entry and run “cat trace”. But I got no output of the hda trace events.

Did you forget to do: # echo 1 > tracing_on

You might also want to set current_tracer to something.

Otherwise I don't know what the problem can be.