On Sat, Sep 13, 2008 at 10:24:29AM -0400, Jeff Garzik wrote:
> 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.
>>
>> 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);
>
>
> This is a bit surprising, considering that libata works for all IDE mode
> of other controllers...
The problem is that when the M5229 is embedded into an M1543, the
PCI IRQ is ignored, and the IRQ is routed directly into the ISA-PIC
in the M1543. This routing is done via a different set of configuration
registers, so that each channel can have its own IRQ.
This means that in pci-native mode, there is no pcidev.irq field set,
as there is no PCI IRQ setup. Alan Cox has stated that this is too
broken to be worked around in libata.
--
Ben (ben@xxxxxxxxx, http://www.fluff.org/)
'a smiley only costs 4 bytes'
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