[alsa-devel] [PATCH] ASoC: Ensure we delay long enough for WM8994 FLL to lock when starting

Mark Brown broonie at opensource.wolfsonmicro.com
Wed Jul 27 14:18:55 CEST 2011

On Mon, Jul 04, 2011 at 10:13:56AM +0900, Sangbeom Kim wrote:
> Is there any checking method for locking FLL?
> (ex. Checking register bit for FLL lock)

There is an interrupt which I've got a patch to use (it's in need of a
bit more testing so not yet published).  You can also poll the status
bits but on a lot of systems that works out as being too expensive due
to I/O costs.

> Just using msleep looks not enough to ensure FLL lock.

Practically speaking it's fine; the FLL lock time is specified
performance characteristic of the device.  If we can't lock when we
expect to then the system is in trouble and it's not clear what we can
do about usefully. 

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