Re: [uCsimm] Interrupts & ColdFire

From: Greg Ungerer (
Date: Thu Jun 29 2000 - 20:02:58 EDT

Hi Olivier,

Olivier Bouyssou wrote:
> In my design I use a st16c2550 device from Exar (a 16550A like). One of
> his interrupt line is connected to IRQ7 of the 5206e.
> My problems occur when i use this device : the kernel freeze and
> enter in a infinit loop after a variable time of use.
> So my questions are :
> - Does the driver (serial.c) for the 16550 of the uClinux distribution
> for ColdFire work correctly ?

Yep, I use it with a Connectix modem chip (which has built in 16550

> - Is it possible to use the interruptions of level 7 without affected
> the operation of the kernel ?

Most definately. IRQ7 is special on the ColdFire's. It is, when enabled,
a Non-maskable interrupt. The usual cli/sti protections don't apply
to it. So the code for something like the serial.c driver is simply
not going to work as you expect.

I would strongly recommend using another IRQ line if you have one spare.


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