In message <3F0C6C0C.8040306 at earthlink.net> you wrote:
>
> >Solution? What is so difficult about latching your output value in a
> >variable?
> >
> What he's saying is that OTHER drivers read the input and then write
> that value to the output.
I did understand this.
> In his driver, he can latch the output through a variable, but that
> won't affect what other
Obviously all drivers that may modify bits in this I/O port will have
to share the variable used to latch the value.
Yes, this may include modifying existing code in the UART or Ethernet
or other drivers.
> Unless there is kernel support to alias the data in a memory variable
> (and it doesn't sound like
> there is), then this is going to continue to be a problem. Might I
Don't make it unnecessary complicated. You don't need "kernel support
to alias the data in a memory variable". This is really not so
difficult to implement yourself when you need it.
Best regards,
Wolfgang Denk
--
Software Engineering: Embedded and Realtime Systems, Embedded Linux
Phone: (+49)-8142-4596-87 Fax: (+49)-8142-4596-88 Email: wd at denx.de
The so-called "desktop metaphor" of today's workstations is instead
an "airplane-seat" metaphor. Anyone who has shuffled a lap full of
papers while seated between two portly passengers will recognize the
difference -- one can see only a very few things at once.
- Fred Brooks, Jr.
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