Re: [Patch/RFC]: check CONFIG_GENERIC_HARDIRQS for request/free_irq in interrupt.h

[Christian Borntraeger <borntraeger@de.ibm.com>]

Am Donnerstag, 29. Mai 2008 schrieb Martin Schwidefsky:
> On Thu, 2008-05-29 at 17:41 +0200, Christian Borntraeger wrote:
> > I currently try to evaluate virtio_console for kvm on s390 and got
> > the following problem:
> > 
> > virtio_console uses hvc_alloc with irq=0. That means, register_irq
> > and free_irq are never called by hvc_console.c, but the linker will
> > still complain about unknown references to free_irq and request_irq.
> > 
> > As the whole kernel/irq folder depends on CONFIG_GENERIC_HARDIRQS 
> > it seems consistent to declare all functions from kernel/irq only if
> > CONFIG_GENERIC_HARDIRQS is set. Otherwise we can use empty functions.
> > 
> > This patch does that for register_irq and free_irq. 
> > 
> > Comments?
> 
> Please don't. So far whenever the linker complained about the missing
> register_irq/free_irq functions it has been a bug in a Kconfig file.
> We should not silently accept code that requires the concept of an
> irq-line when there is no such thing on a s390.

Ok, convinced.

I will look if I can modify virtio_console to get rid of hvc_console. Reading
all the comments, it appears that Rusty is not really happy with all the 
dependencies/limitations that hvc_console brings to virtio_console.

Rusty, be prepared.... ;-)

Christian