[LAD] Writing a driver for a device which clears the buffer on the start trigger

[Adrian Knoth]

On Wed, Jul 31, 2019 at 09:34:45PM +0200, Paul Pawlowski wrote:

> Hello,

Hi!

> I have got the driver working to some extent by moving the Start IO command
> code to the open() callback instead of the trigger(SNDRV_PCM_TRIGGER_START)
> however that's obviously a hack and causes issues (the first ~0.1s of audio
> is lost).

You're probably better off on alsa-devel@:

   https://alsa-project.org/wiki/Mailing-lists#alsa-devel_at_alsa-project.org


I have no good immediate solution to offer (I lost touch with Linux
audio 5yrs ago, don't know why I'm still on this list :) ). Maybe you
can even start streaming in the chip init function and track in a
bool whether this is the actual stream or not. If not, then send
silence (memset the buffer, so that there's no noise), and only send
real data if there was a start command.

Terrible hack and obviously bad for power consumption.

I'm sure Takashi has better ideas on alsa-devel at . ;)

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