Re: Shared Interrupts Question (2.4)

Hi

U r saying from the interrupt controller only one
physical line is coming to CPU to interrupt CPU.

SO in the do_irq routine u will have to read the
interrupt controller registers & find out who has
caused the interrupt & then invoke interrupt handler
corressponding to the interrupt number.

U should have a way, from the CPU to read the
interrupt controller registers & find out the
cause.....................


Bhupi
Linux+Hypertransport -->Silicon
www.gdatech.com
Good after beer -- Linux

--- Kent Borg <kentborg@borg.org> wrote:

I am trying to understand "kinda shared" interrupts.

There are various interrupts in my not-yet-released
CPU, and I have
interrupt code that knows how to talk to them.  So
far so good.  I
also have an external interrupt controller that
groups together 18
external interrupt sources and sends them in one CPU
pin.  This
external controller has a register for enabling
interrupts, and a
register for status/acknowledge.  Pretty standard.

The CPU code doesn't know about the external
controller.  It seems
silly to rewrite the CPU-specific interrput code to
accommodate this
board-specific detail (besides then my code won't
match Dale's).  So I
figure I tell the kernel I am doing shared
interrupts.

So where do I enable, disable, and acknowledge these
external bits?
Specifically, I am trying to get a couple of serial
ports working.  I
can put conditional code in serial.c startup() to
enable these
interrupts, but how do I know which serial port?
Add a conditionally
compiled sub-IRQ number to serial_state structure?

Is there a cleaner way?


Thanks,

-kb

** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/