This will be OK to test XRUN condition in driver. XRUN will be reported in either of these functions static inline int snd_pcm_update_hw_ptr_interrupt(struct snd_pcm_substream *substream) or static inline int snd_pcm_update_hw_ptr_post(struct snd_pcm_substream *substream, struct snd_pcm_runtime *runtime) or you can put some Debug logs in static void xrun(struct snd_pcm_substream *substream) All these functions are in sound/core/pcm_lib.c When we stop the application by issuing Ctrl-Z then onwards application will not write/read data from device. So driver will go to XRUN state, when driver detects XRUN it stops the substream by calling snd_pcm_stop() (inside xrun()). But application cannot detect this because he is not active. But when we activate application (fg) then it detects -EPIPE (stopped substream), then application prepare it snd_pcm_prepare() and starts the playback(substream) again. Nobin On 6/8/07, Eliot Blennerhassett <linux@xxxxxxxxxxxxxxxx> wrote: > Hi, > > I want to test my driver behaviour when an xrun happens. > > I have tried using aplay/arecord, and suspending (ctrl-Z) them while > playing/recording but this doesn't have the desired effect. (I don't see my > driver code detecting an xrun). Instead I see a trigger-stop command to the > driver. > > The apps do report an overrun when they are restarted though. > > Can anyone answer these: > > 1) Is this a valid way to simulate an xrun due to application not keeping up? > > 1.1) If not, what is? Do I have to write an app that deliberately starves the > streams? > > 2) Where is the xrun being detected if my driver doesnt see it? Where does > the trigger-stop command come from when I suspend the app? > > thanks > > Eliot Blennerhassett > AudioScience Inc. > _______________________________________________ > Alsa-devel mailing list > Alsa-devel@xxxxxxxxxxxxxxxx > http://mailman.alsa-project.org/mailman/listinfo/alsa-devel > _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
