i was getting those overrun issue because of one controller bug, if i write zero to TXCR/RXCR register to disable both transmit and receive logic before low power mode then i am getting this overrun error after resume.
Thanks a lot for your help
Thanks Nobin Mathew
On 5/28/07, Nobin Mathew nobin.mathew@gmail.com wrote:
I think i found the issue. Issue is in controller. Soon i will get back with more details
On 5/28/07, Nobin Mathew nobin.mathew@gmail.com wrote:
I did some more investigation into this issue.
There are two cases, in the first case it is working after resume() and in the second case it is not working after resume
1st Case:
- boot the system
2)Load sound modules 2)mixer setting (alsactl restore 0) 3)Do power managemnt (sleep) suspend() 4)Come out of suspend, resume() 5) sound is coming out in this case
2nd Case: 1)boot the system 2)load sound modules 3)mixer settings (alsactl restore 0) 4)Do playback aplay -M /usr/share/sounds/alsa/Side_Right.wav 5) Let aplay to completion and kill all alsa apps if any running. 6)Do power managemnt (sleep) suspend() 7)Come out of suspend, resume() 8)Do playback aplay -M /usr/share/sounds/alsa/Side_Right.wav
in this case no sound is coming out and i am getting underrun error.
I am attaching some logs, these are the ac97 codec register values at various stages.
Mainly look at the register 3c.
On 5/25/07, Takashi Iwai tiwai@suse.de wrote:
At Fri, 25 May 2007 13:39:40 +0100, Liam Girdwood wrote:
On Fri, 2007-05-25 at 17:34 +0530, Nobin Mathew wrote:
Every ALSA driver is calling these for suspend
snd_power_change_state(card, SNDRV_CTL_POWER_D3hot); snd_pcm_suspend_all(pcm[i]);
And for resume snd_power_change_state(card, SNDRV_CTL_POWER_D0)
In ALSA ASoC no driver is calling any of this, even not in soc-core.c
My driver is an ASoC driver and I am also not calling these functions
Will this cause any Issue?
These should probably be called to inform the upper layers of the PM state. Can you log a bug for this in ALSA bugzilla.
Fwiw, this _shouldn't_ effect your resume. You should still see calls to trigger for your DMA / AC97 to re-start transmission of PCM data.
I think this does matter. Without calling snd_pcm_suspend*(), the stream is assumed to be still active, thus eventually neither prepare nor trigger is called at resume. If the hardware is perfectly resumed as it was before suspend, it may still work somehow.
However, usually it's impossible to resume the hardware perfectly. Thus, we need one stop the stream via snd_pcm_suspend*(), and let apps (or OSS layer) parepare (if needed) and restart the stream again.
Takashi