Hi Sakamoto-san Thank you for your feedback > > Our sound device needs recovery if under/over run error happen. > > Basically, this "recovery" means "restart hardware". > > But, in such case, who should recovers sound device, Kernel or Userland ? > > > > Current our sound driver recovers it by kernel automatically. > > (But I need do work more for it) > > I think you should not recover it in kernel space, because 'hw_ptr' in > mapped page includes values unexpected by userspace application. (The > value may suddenly jump up to unexpected value after recovered.) > > What driver in kernel land is to notify XRUN to the applications in > your case. If recovering processing includes event waiting, it should > not be executed in interrupt context. > > > We considered that userland should know it, or, run it by himself (?) > > If userland should do it, which function should be called to announce > > error to userland from kernel ? > > Userspace can get to know the XRUN state by calling some APIs. Then, > it can recover PCM substream by executing SNDRV_PCM_IOCTL_PREPARE > ioctl. I think we can use snd_pcm_stop_xrun() for this purpose. I will try to investigate it. _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxx http://mailman.alsa-project.org/mailman/listinfo/alsa-devel
