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' -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html