Date: Tue, 7 Jan 1997 18:00:51 -0700 (MST) From: Nate Williams <nate@mt.sri.com> To: current@freebsd.org Subject: Kernel driver advice Message-ID: <199701080100.SAA28576@rocky.mt.sri.com>
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This is regards to the recent kernel PR. Basically, the current PCCARD
code uses IRQ3, which is the standard IRQ used on COM2/sio1.
Suffice it to say that this is a 'Bad Thing'.
There is nowhere in the kernel config file to tell the system that it's
using IRQ3, or to even tell it to use something else (other than to use
Yet Another option.
The 'best' solution would be to change it's config line from:
device crd0
to
device crd0 at isa? irq 5
or any free interrupt that should be in the system.
However, this means that the 'theoretically' machine-dependant pccard
code is now directly tied to the isa bus, and it's location in
/sys/pccard is wrong, and it should be moved to /sys/i386/pccard.
To be honest, the code already has lots of isa specific parts in it, so
it's really not isa/i386 independant, but that's mostly the case of
FreeBSD's x86 specific layout.
Also, the existing setup isn't really 'isa' specific, but since the ISA
bus is the only 'connection' for things such as IRQ's, there is no other
way of registering an IRQ in FreeBSD except as an isa driver.
Is there a better/different way of registering the need for an interrupt
and *NOT* being an ISA device? How do the PCI devices grab an
interrupt?
Finally, is there a way to request the list of used/unused IRQ's in the
system at a point in time? I'd like to be able to check if a particular
IRQ is used in the system at probe time, and if it's already allocated
to try different IRQ's until one is available.
If at all possible, I'd like to wait until all of the other probe's are
done, and then I'd be able to get a list of available interrupts to use
for the PCIC controller *and* for the PCMCIA cards.
Is *any* of this do-able with our current FreeBSD kernel?
Nate
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