Re: [PATCH] Add SATA device to VIA IRQ quirk fixup list

From: Sergio Monteiro Basto
Date: Wed Jul 26 2006 - 08:50:33 EST

Hi, Alan

But can we know if dev->irq is XT-PIC ? or not ?
or could we know if IO_APIC or LOCAL_APIC is enabled or
not ?

on linux-2.6.17/drivers/pci/quirks.c

* we must mask the PCI_INTERRUPT_LINE value versus 0xf to get
* interrupts delivered properly.

static void quirk_via_irq(struct pci_dev *dev)
u8 irq, new_irq;

I want put here something like: if ( dev->irq != XT-PIC) return and
don't quirk this dev.

new_irq = dev->irq & 0xf;
pci_read_config_byte(dev, PCI_INTERRUPT_LINE, &irq);

On Wed, 2006-07-26 at 01:42 +0100, Alan Cox wrote:
> A few comments
> "The legacy IDE is using IRQ 14 or 15 not PCI"
> This is half correct - V-Link is not involved in this case, however the
> legacy IRQs are configurable and steerable via func 0 reg 0x4C for some
> chips. If this has been set by a weirdass bios (bits 3-0 not 0x0100 for
> the 8233C varies for others) then we've never supported it.
> I have full IRQ routing info for some of the VIA chips and it varies by
> chip how this all works.
> The 8233/8233C routes via register 0x4C/0x4D of function 0 for internal
> devices and via 0x55->0x57 (polarities on 0x54) for PCI interrupts. The
> devices use the IRQ number not line. Also to add fun the 8233C has a
> 3com nic part that does this...
> There are then a seperate set of register mappings for SCI and for ISA
> IRQ mapping.
> There is an errata with the internal devices of the 8235 and earlier
> which can be used to detect them fairly well. Only the low four bits of
> 0ffset 0x3C are writable not the full IRQ value.
> Some later chips use bits to indicate PIC v APIC routing.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at
> Please read the FAQ at
Sérgio M.B.

Attachment: smime.p7s
Description: S/MIME cryptographic signature