Re: regression on quad Xeon: no SCSI-disks

[Wolfgang Erig <Wolfgang.Erig@gmx.de>]

On Fri, May 04, 2007 at 03:18:54AM +0400, Ivan Kokshaysky wrote:
> On Thu, May 03, 2007 at 10:41:41AM +0200, Wolfgang Erig wrote:
> > I am prepared to do tweaks to your small patch, but I need your help.
> > My own blindly experiments failed miserably.
> 
> I don't think that patch did anything wrong, most likely it just
> triggered a bug elsewhere. These two lines from your dmesg look
> very suspicious:
> 
> > PCI: Cannot allocate resource region 0 of device 0000:00:04.0
> > PCI: Error while updating region 0000:00:04.0/0 (a8008000 != fec08000)
> 
> Note that the BAR seems to have high address bits hardwired to fec00000.
> And device 0000:00:04.0 is
> > 00:04.0 System peripheral: Siemens Nixdorf AG FSC Multiprocessor Interrupt Controller (rev 02)
> 
> I'd guess that when we try to reassign this resource, PCI interrupts might
> just stop working. This could explain SCSI timeouts and other weird things.
> 
> Maybe this patch helps?
> 
> Ivan.
> 
> --- 2.6.21/arch/i386/pci/fixup.c	2007-02-04 21:44:54.000000000 +0300
> +++ linux/arch/i386/pci/fixup.c	2007-05-04 01:58:32.629654275 +0400
> @@ -436,3 +436,14 @@ DECLARE_PCI_FIXUP_EARLY(PCI_VENDOR_ID_CY
>  			pci_early_fixup_cyrix_5530);
>  DECLARE_PCI_FIXUP_RESUME(PCI_VENDOR_ID_CYRIX, PCI_DEVICE_ID_CYRIX_5530_LEGACY,
>  			pci_early_fixup_cyrix_5530);
> +
> +/*
> + * Siemens Nixdorf AG FSC Multiprocessor Interrupt Controller:
> + * prevent update of the BAR0, which doesn't look like a normal BAR.
> + */
> +static void __devinit pci_siemens_interrupt_controller(struct pci_dev *dev)
> +{
> +	dev->resource[0].flags |= IORESOURCE_PCI_FIXED;
> +}
> +DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_SIEMENS, 0x0015,
> +			  pci_siemens_interrupt_controller);
> -
bingo, this works.
If it makes sense, please send this to Linus.

Thanks a lot,
Wolfgang