Interfacing user application and interrupt.

Interfacing user application and interrupt.

[John Francis]

Hello,

I have a situation where one of the controller on my
board can generate interrupt which I am planning to
use as a signal for a user process to go and read some
data from "serial port or socket".

How is this task commonly done?

What I want to happen is

A *UNIX user process* waits for interrupt to go off.
When the interrupt is generated it goes and reads from
/dev/tty or a socket.

I also have ppc linux interrupt handler that correctly
detects the interrupt from the device. Now what I am
missing is how does the kernel interrupt handler
indicate to the user process that  there was an
interrupt and user process needs to do its thing....

Any pointers on how to do this properly?

-John

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Re: Interfacing user application and interrupt.

[Wolfgang Denk]

In message <20010721101345.5964.qmail@web20104.mail.yahoo.com> you wrote:
>
> I also have ppc linux interrupt handler that correctly
> detects the interrupt from the device. Now what I am
> missing is how does the kernel interrupt handler
> indicate to the user process that  there was an
> interrupt and user process needs to do its thing....

Either make your user process block in a read / write / ioctl  system
call,  and  wake  it  from  your  interrupt  handler,  or implement a
select() / poll() interface, so you don't have to block  waiting  for
this event alone.

Wolfgang Denk

--
Software Engineering:  Embedded and Realtime Systems,  Embedded Linux
Phone: (+49)-8142-4596-87  Fax: (+49)-8142-4596-88  Email: wd@denx.de
In C we had to code our own bugs, in C++ we can inherit them.

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