[alsa-devel] [PATCH 1/4] ASoC: sgtl5000: give it a ramping time before writting
marex at denx.de
Mon Jul 1 12:54:18 CEST 2013
Dear Mark Brown,
> On Mon, Jul 01, 2013 at 04:16:08PM +0800, Shawn Guo wrote:
> > + /*
> > + * It seems that sgtl5000 takes a longer time to get the registers
> > + * ready for write than bread. Let's give it a ramping time before
> > + * the first write goes.
> > + */
> > + msleep(50);
> > +
> > /* Ensure sgtl5000 will start with sane register values */
> > ret = sgtl5000_fill_defaults(sgtl5000);
> > if (ret)
> This seems like a really odd place to add the sleep - I'd have expected
> this to be a part of or just after the reset operation. It's a *really*
> long sleep too, though if that's what you need that's what you need.
The delay might also be caused by the I2C driver, I have this in my ToDo to
check, but I didn't get to it yet. On the other hand, if subsequent IO does
work, then it's unlikely to be the case.
> Also "bread" :)
Of course, sometimes you want to put a lot of things on it, like bacon and such.
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