Date: Thu, 07 Apr 2005 10:43:15 -0700 From: Nate Lawson <nate@root.org> To: John Baldwin <jhb@FreeBSD.org> Cc: Antoine Brodin <antoine.brodin@laposte.net> Subject: Re: Interrupt storm Message-ID: <42557133.2070802@root.org> In-Reply-To: <200504051349.13620.jhb@FreeBSD.org> References: <b37cb09705032911295ce15f84@mail.gmail.com> <200504051110.35735.jhb@FreeBSD.org> <20050405185831.2484695e.antoine.brodin@laposte.net> <200504051349.13620.jhb@FreeBSD.org>
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John Baldwin wrote:
> Ok, I see the issue now. The problem is that the BIOS sets the IRQ registers
> in the PCI devices to values that don't match how the links are programmed
> and we tend to trust the BIOS over the links in those cases. Can you tell me
> what IRQ sk0 gets if you don't use ACPI? Does it get 5 or 9? If it gets 9,
> does it work ok?
>
> You can try this patch for ACPI. Unfortunately, some BIOSes lie when you ask
> a link which IRQ it is routed to, so I'm not sure if this patch can be
> committed as is. Nate, do you know if such BIOSen only return no IRQ at all
> (0 or 255) when they lie rather than a bogus "valid" IRQ?
>
> --- //depot/vendor/freebsd/src/sys/dev/acpica/acpi_pci_link.c 2005/01/18
> 20:21:25
> +++ //depot/user/jhb/acpipci/dev/acpica/acpi_pci_link.c 2005/04/05 17:46:46
> @@ -621,14 +622,16 @@
> device_printf(dev, "BIOS IRQ %u for %d.%d.INT%c is invalid\n",
> bios_irq, pcib_get_bus(pcib), slot, pin + 'A');
> } else if (!PCI_INTERRUPT_VALID(link->l_bios_irq)) {
> - link->l_bios_irq = bios_irq;
> - if (bios_irq < NUM_ISA_INTERRUPTS)
> - pci_link_bios_isa_irqs |= (1 << bios_irq);
> if (bios_irq != link->l_initial_irq &&
> PCI_INTERRUPT_VALID(link->l_initial_irq))
> device_printf(dev,
> "BIOS IRQ %u does not match initial IRQ %u\n",
> bios_irq, link->l_initial_irq);
> + else {
> + link->l_bios_irq = bios_irq;
> + if (bios_irq < NUM_ISA_INTERRUPTS)
> + pci_link_bios_isa_irqs |= (1 << bios_irq);
> + }
> } else if (bios_irq != link->l_bios_irq)
> device_printf(dev,
> "BIOS IRQ %u for %d.%d.INT%c does not match previous BIOS IRQ %u\n",
When link devices are uninitialized by the BIOS, you usually get an
invalid IRQ (i.e. 255 or 0). However, there are some cases where you
get a valid PCI irq but invalid for this system (i.e. not in the
supported ones advertised by _PRS). For instance, you might get a value
of 15 for a link that only supports 3,4,5,6,7,9, etc. I think you
should be checking _PRS for validity, not just PCI_INTERRUPT_VALID (i.e.
!255). Aren't you doing that already?
--
Nate
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