[alsa-devel] [PATCH 08/11] ARM: OMAP3: Remove callback for McBSP sidetone ICLK workaround

Jarkko Nikula jarkko.nikula at bitmer.com
Wed Aug 8 15:25:05 CEST 2012

On 08/08/2012 12:11 PM, Peter Ujfalusi wrote:
> We can achieve the same result with SIDLEMODE field within McBSP SYSCONFIG
> register.
> The ASoC driver has been modified to use this method and we can now remove
> the workaround using the control module register.
Are you sure it works without any changes to sidetone audio quality or
current consumption? What I remember idlemode was broken at least on
3430 and caused bad sidetone audio if autoidle was set and a little bit
higher current consumption (something like 2-3 mA higher where reference
consumption was around 10 mA) when McBSP was set to no-idle.

Here's the old thread:


I think I tested all of this by using arecord >/dev/null | aplay
/dev/zero with threshold based DMA transfers with all bells and whistles
set for dynamic retention idle in order to hear only McBSP sidetone
while measuring current consumption.

But I guess 2-3 mA higher consumption is ok if it simplifies SW a lot
and base consumption is anyway much higher than 10 mA when sidetone is
in real use (my test above was artificial where actual use is under a
phone call with heavy consumption from cellular modem etc).


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