Re: [PATCH] gpio-sch: set output level after configuration of direction

[Gerhard Sittig <gsi@xxxxxxx>]

On Tue, 2014-03-25 at 10:33 +0100, Alexander Stein wrote:
> 
> According to the datasheet, writing to the level register has no effect
> when GPIO is programmed as input. Hence we set the level after configuring
> the GPIO as output. But we cannot prevent a short low pulse if direction is
> set to high and an external pull-up is connected.

Does "will have no effect" actually translate into "should not be
done" or even "must not be done"?  Doesn't sound like it.

I understood that setting the data register for input pins does
nothing in that very moment, yet when switching to output the
value immediately gets used.  So this is the most appropriate
thing to do.


virtually yours
Gerhard Sittig
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