Re: [PATCH] PCI legacy resource fix

[Ralf Baechle <ralf@linux-mips.org>]

On Fri, Dec 08, 2006 at 07:46:18PM -0500, Ben Collins wrote:

> On Wed, 2006-12-06 at 13:41 +0000, Ralf Baechle wrote:
> > Since commit 368c73d4f689dae0807d0a2aa74c61fd2b9b075f the kernel will try
> > to update the non-writeable BAR registers 0..3 of PIIX4 IDE adapters if
> > pci_assign_unassigned_resources() is used to do full resource assignment
> > of the bus.  This fails because in the PIIX4 these BAR registers have
> > implicitly assumed values and read back as zero; it used to work because
> > the kernel used to just write zero to that register the read back value
> > did match what was written.
> > 
> > The fix is a new resource flag IORESOURCE_PCI_FIXED used to mark a
> > resource as non-movable.  This will also be useful to keep other import
> > system resources from being moved around - for example system consoles
> > on PCI busses.
> 
> I have a problem where an ich6 (SATA+PATA) is getting its port0 reserved
> by the pci quirk for libata so that it gets picked up by ata_piix. In
> current git, ata_piix complains:
> 
> [  124.507570] PCI: Unable to reserve I/O region #1:8@1f0 for device 0000:00:1f.2
> 
> I bisected to the same commit, 368c73d4f689dae0807d0a2aa74c61fd2b9b075f,
> however, your patch doesn't fix my problem.

Looks like a double reservation.  My patch doesn't deal with reservations
at all.  I thought about resource reservations but decieded that should
be dealt with elsewhere.

  Ralf