[alsa-devel] Fwd: ALSA queries

[Chakravarthi Pradeep]

Dear Takashi,

In previous mail you have mentioned
> So, either the measurement is wrong, or the stream is already screwed
> up at the time you call snd_pcm_period_elapsed().

what it means "measurement is wrong"  and how to make that measurement
is correct ?

Regards,
Chakravarthi
On Tue, Aug 7, 2018 at 5:33 PM Takashi Iwai <tiwai at suse.de> wrote:
>
> On Tue, 07 Aug 2018 13:59:46 +0200,
> Chakravarthi Pradeep wrote:
> >
> > Dear Takashi,
> >
> > Trigger stop is getting called , because of this hwptr is zero and
> > pointer call back is not getting called. Below is my log from driver.
> >
> > [  838.491681] Trigger:Start
> > [  839.522233] hwptr=0 buf_pos:3456
> > [  839.522244] buf_pos :3456 bytes_to_frames:864 uhdc_audio_pcm_pointer_253
> > [  839.522249] Trigger:Stop
>
> Then you need to figure out the code path of the trigger stop.
>
> > In normal scenario, Trigger stop is not getting called and audio was
> > able to render in the VLC application. Below log for normal scenario,
> > [  802.785893] Trigger:Start
> > [  814.288309] hwptr=0 buf_pos:6272
> > [  814.288323] buf_pos :6272 bytes_to_frames:1568 uhdc_audio_pcm_pointer_253
> > [  814.288362] buf_pos :6272 bytes_to_frames:1568 uhdc_audio_pcm_pointer_253
> > [  814.288378] buf_pos :6272 bytes_to_frames:1568 uhdc_audio_pcm_pointer_253
> > [  814.305079] hwptr=6272 buf_pos:9472
> > [  814.305091] buf_pos :9472 bytes_to_frames:2368 uhdc_audio_pcm_pointer_253
> > [  814.321741] hwptr=9472 buf_pos:12672
> > [  814.321748] buf_pos :12672 bytes_to_frames:3168 uhdc_audio_pcm_pointer_253
> > [  814.321777] buf_pos :12672 bytes_to_frames:3168 uhdc_audio_pcm_pointer_253
> > [  814.321785] buf_pos :12672 bytes_to_frames:3168 uhdc_audio_pcm_pointer_253
> > [  814.338452] hwptr=12672 buf_pos:15872
> > [  814.338459] buf_pos :15872 bytes_to_frames:3968 uhdc_audio_pcm_pointer_253
> > [  814.355242] hwptr=15872 buf_pos:19072
> > [  814.355248] buf_pos :19072 bytes_to_frames:4768 uhdc_audio_pcm_pointer_253
> > [  814.355288] buf_pos :19072 bytes_to_frames:4768 uhdc_audio_pcm_pointer_253
> > [  814.355294] buf_pos :19072 bytes_to_frames:4768 uhdc_audio_pcm_pointer_253
> > [  814.371822] hwptr=19072 buf_pos:22272
> > ...
> > ...
> > [  830.739031] Trigger:Stop
> >
> >
> > I can not do rmmod for ALSA driver. If I do sudo rmmod mydriver then it says
> > "rmmod: ERROR: Module mydriver is in use"
> >
> > How can I remove mydriver module from linux kernel ?
>
> Likely some program is using the sound device.  For example, a mixer
> applet or PulseAudio keeps opening the control device.
> Check it via "fuser -v /dev/snd/*"
>
>
> Takashi



-- 
Thanks and Regards
Chakravarthi Pradeep.K
Ph: 91 9980434900