[alsa-devel] [PATCH - alsa-lib] pcm/ioplug: Add mutex in snd_pcm_ioplug_hw_ptr_update

Function snd_pcm_ioplug_hw_ptr_update can be called from many threads, we need to protect the hw_ptr. I came across this issue with GStreamer and Jackd. Function will be called from the thread doing snd_pcm_write and another would be to get the playback position for the track bar.

Change in itself is very minimum, but it took me a lot of time to debug.

Thanks, Vishal Agrawal