[alsa-devel] how to update hw_ptr and appl_ptr

[Zhen Fu]

I recently write squ driver and when DMA handler called snd_pcm_period_elapsed, so I want to know how about update hw_ptr in ALSA. 

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Best Regards,
Zhen Fu


-----Original Message-----
From: Clemens Ladisch [mailto:clemens at ladisch.de] 
Sent: Tuesday, June 26, 2012 5:35 PM
To: Zhen Fu
Cc: alsa-devel at alsa-project.org
Subject: Re: [alsa-devel] how to update hw_ptr and appl_ptr

Zhen Fu wrote:
> I recently look the function snd_pcm_update_hw_ptr0 want to  find how
> to update status->hw_ptr and control->appl_ptr.

status->hw_ptr is updated by snd_pcm_update_hw_ptr0.  control->appl_ptr
is updated by snd_pcm_lib_write1.

Why are you asking?


Regards,
Clemens