Re: best way to handle LEDs

[Pavel Machek]

Hi!

> > > > Except the led code that is being proposed CAN sit on top of a generic
> > > > GPIO layer.
> > > 
> > > I also have issues with a generic GPIO layer.  As I mentioned in the
> > > past, there's serious locking issues with any generic abstraction of
> > > GPIOs.
> > > 
> > > 1. You want to be able to change GPIO state from interrupts.  This
> > >    implies you can not sleep in GPIO state changing functions.
> > > 
> > > 2. Some GPIOs are implemented on I2C devices.  This means that to
> > >    change state, you must sleep.
> > 
> > Can't you just busywait? Yes, it is ugly in general, but perhaps it
> > is better than alternatives...
> 
> Does the i2c layer support busy waiting or are you suggesting something
> else?

I'm suggesting that adding busy wait support to i2c is probably good
idea. GPIOs are on many small machines, and there are machine
(spitz/akita?) that differ mainly in "where GPIO lines are
connected". That cries for GPIO layer.
							Pavel
-- 
Thanks, Sharp!
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