Re: 2.6.8-rc3-mm2

Russell King
2004-08-10T13:52:06Z

On Tue, Aug 10, 2004 at 03:16:28PM +0200, Ingo Molnar wrote:
>
> * Russell King <rmk+lkml@arm.linux.org.uk> wrote:
>
> > Except serial console IO does not generate _any_ IRQ traffic - it
> > purposely disables IRQs on the device before starting any IO to
> > prevent any user-level IO interfering with the console output.
>
> indeed - but it does generate _some_ IRQ traffic still:
>
> 3: 251 IO-APIC-edge serial
>
> this is from a box that uses the serial line only for the kernel
> console.

If the IRQ is claimed, userspace has opened the port. Is a getty
running on the port? If so, it would've written some messages to
the port, which would have caused these interrupts.

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 PCMCIA - http://pcmcia.arm.linux.org.uk/
2.6 Serial core