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

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.

But I switch to the original kernel in Ubuntu 13.04 or 13.10 and repeat the above steps, I can get the output of hda trace events.

Thanks Mengdong