Re: PCI: Add ALI M5229 comaptibility mode quirk

From: Matthew Wilcox
Date: Fri Sep 12 2008 - 08:34:15 EST


On Fri, Sep 12, 2008 at 12:22:52PM +0100, Ben Dooks wrote:
> The libata driver will not work with an M5229 set into native IDE
> mode (the old drivers/pci one does) if the M5229 does not provide
> it's own IRQ.
>
> The M5229 implementation embedded into the ALI M1543 uses the
> M1543's ISA PIC to provide the interrupts and thus does not have
> an valid PCI IRQ set. This quirk detects the abscence of IRQ and
> sets the M5229 back into compatibility mode to use IRQs 14 and 15
> so that libata works correctly.
>
> Note, I belive that the check for an valid interrupt line is
> correct, I only have an M5229 in an ALI M1543 to check this
> on. It would be useful to confirm that a M5229 with an valid IRQ
> does not trigger this quirk.

Why does this need to be a quirk rather than something in the libata ALi
driver?

> Signed-off-by: Ben Dooks <ben-linux@xxxxxxxxx>
>
> Index: linux-2.6.27-rc6-cats1/drivers/pci/quirks.c
> ===================================================================
> --- linux-2.6.27-rc6-cats1.orig/drivers/pci/quirks.c 2008-09-11 11:26:35.000000000 +0100
> +++ linux-2.6.27-rc6-cats1/drivers/pci/quirks.c 2008-09-12 12:18:05.000000000 +0100
> @@ -905,6 +905,34 @@ static void __devinit quirk_svwks_csb5id
> }
> DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_SERVERWORKS, PCI_DEVICE_ID_SERVERWORKS_CSB5IDE, quirk_svwks_csb5ide);
>
> +/* Some systems set the ALI M5229 in the ALI M1543 bridge to native mode,
> + * which cannot be supported by the pata_ali.c driver (the old drivers/ide
> + * makes a compatibility effort to change the IDE interrupts).
> + */
> +static void __devinit quirk_ali_ide_compatibility(struct pci_dev *pdev)
> +{
> + u8 tmp;
> +
> + /* pdev->irq and pdev->pin have yet to be initialised, so check
> + * by reading from the configuration header to see if we've got
> + * a valid interrupt line. */
> +
> + pci_read_config_byte(pdev, PCI_INTERRUPT_LINE, &tmp);
> + if (tmp != 0xff)
> + return;
> +
> + pci_read_config_byte(pdev, PCI_CLASS_PROG, &tmp);
> + if (tmp & 0x5) {
> + dev_info(&pdev->dev, "quirk: changing to IDE compatibility mode\n");
> +
> + tmp &= ~0x05;
> + pdev->class &= ~0x05;
> + pci_write_config_byte(pdev, PCI_CLASS_PROG, tmp);
> + }
> +}
> +
> +DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_AL, PCI_DEVICE_ID_AL_M5229, quirk_ali_ide_compatibility);
> +
> /*
> * Intel 82801CAM ICH3-M datasheet says IDE modes must be the same
> */
>
> --
> Ben (ben@xxxxxxxxx, http://www.fluff.org/)
>
> 'a smiley only costs 4 bytes'
> --
> To unsubscribe from this list: send the line "unsubscribe linux-pci" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at http://vger.kernel.org/majordomo-info.html

--
Matthew Wilcox Intel Open Source Technology Centre
"Bill, look, we understand that you're interested in selling us this
operating system, but compare it to ours. We can't possibly take such
a retrograde step."
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/