Date: Sat, 09 Oct 2004 21:16:15 -0600 (MDT) From: "M. Warner Losh" <imp@bsdimp.com> To: nate@root.org Cc: oberman@es.net Subject: Re: cvs commit: src/sys/dev/acpica acpi_quirks acpi_timer.c acpivar.h Message-ID: <20041009.211615.109981313.imp@bsdimp.com> In-Reply-To: <4168A67A.2090805@root.org> References: <4167178E.3050303@root.org> <20041009.205301.93208213.imp@bsdimp.com> <4168A67A.2090805@root.org>
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In message: <4168A67A.2090805@root.org>
Nate Lawson <nate@root.org> writes:
: M. Warner Losh wrote:
:
: > In message: <4167178E.3050303@root.org>
: > Nate Lawson <nate@root.org> writes:
: > : Some slots force irq sharing but if you have devices that can't handle
: > : that irq, they fail. This is especially on older systems that have an
: > : ISA and PCI slot that share an irq line.
: >
: > Are there such systems like this that actually work? We've been
: > telling people that they can't share PCI and ISA interrupts because
: > ISA is edge triggered and PCI is level triggered.
:
: My Abit BP6 has such a configuration for the last slot. You can only
: put a PCI card OR ISA card in, not both.
And you MUST use an IRQ that is used by PCI for that ISA slot? The
ISA slots don't share an IRQ with PCI at all. They might share the
slot, but they don't share interrupts because the ISA card dispatches
the interrupts directly through the IRQ lines on the ISA bus, and the
PCI dispatches it through #INT[A-D] through the bridges between the
device and CPU.
Warner
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