Copying my comment from bug 1187453 when running on mako
This may be a timing thing depending on how fast you type, it does not seem very consistent.
It definitely does not occur when long deliberate presses are used.
Turned debug on in ofonod then
tail -f /var/log/syslog | grep DTMF
You will often see the number of the phone app UI but not in the log
Copying my comment from bug 1187453 when running on mako
This may be a timing thing depending on how fast you type, it does not seem very consistent.
It definitely does not occur when long deliberate presses are used.
Turned debug on in ofonod then
tail -f /var/log/syslog | grep DTMF
You will often see the number of the phone app UI but not in the log