sleeping clk_[enable,disable]?
Uwe Kleine-König
u.kleine-koenig at pengutronix.de
Wed Feb 24 03:46:07 EST 2010
Hello,
On Tue, Feb 23, 2010 at 03:32:19PM +0100, Linus Walleij wrote:
> A question here:
>
> If you have a clocking hardware that would actually require
> clk_[enable,disable] to
> sleep in order to ascertain that the clock is actually in the
> requested state when
> you return from these functions, what can you do?
>
> I could think of several solutions, like:
>
> * Actually let clk_[enable,disable] sleep, make sure all drivers only calls them
> in thread context.
>
> * Impose a state in the clk so it can be "in transition", then an
> additional function
> clk_is_stable() which will also have to be added to most drivers but had the
> advantage of not violating the defined clk_[enable,disable] API.
>
> * Throw in udelay():s after the clk_[enable,disable] calls, with some values
> that are unfortunately then spread out in the drivers instead of in the
> clk implementation.
I had a similar problem some time ago, and choosed to let
clk_{en,dis}able sleep.
Best regards
Uwe
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