Subject: Re: Masking out irqs with PCIC_ISA_INTR_ALLOC_MASK in pcmcia subsystem
To: Eric S. Hvozda <firstname.lastname@example.org>
From: Jason Thorpe <email@example.com>
Date: 11/10/1997 10:47:24
On Mon, 10 Nov 1997 08:39:30 -0500
"Eric S. Hvozda" <firstname.lastname@example.org> wrote:
> I dinally got the D-Link DE-650 working, but it seems that irq 9
> is in use on my notebook.
> I understand I can mask this irq out with PCIC_ISA_INTR_ALLOC_MASK.
> However it's not readily apparent to me how 0xfbff masks irq 10
> as documented in /sys/dev/isa/i82365_isa.c. By my calculations
> it would seem this just masks irq 4; so surely I must be missing the
> bigger picture...
You don't mask it _out_. You mask them _in_ :-) 0xffff would allow
IRQs 0 - 15. If you want to not use IRQ 10, you do:
0xffff & ~(1 << 10) -> 0xfbff
...so if you also want to exclude IRQ 9:
0xfbff & ~(1 << 9) -> 0xf9ff
Jason R. Thorpe email@example.com
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