Re: [patch 2.6.12 (repost w/ corrected subject)] pci: restore BAR values in pci_enable_device_bars

Russell King
2005-07-05T22:03:24Z

On Tue, Jul 05, 2005 at 09:05:55PM +0100, Matthew Wilcox wrote:
> On Sat, Jul 02, 2005 at 09:09:13AM +0100, Russell King wrote:
> > The PCI subsystem is incomplete for 64-bit BAR support. What it does
> > do though is ensure that 64-bit BARs will work correctly in a 32-bit
> > system. Therefore, I think that folk who want 64-bit BAR support to
> > work need to do some code reviews on the PCI subsystem to resolve the
> > remaining issues.
>
> 64-bit BARs work fine on 64-bit machines. I'm ambivalent whether we
> ought to support 64-bit BARs on 32-bit machines.

This only occurs because the problematical functions (eg,
pci_update_resource) probably aren't called on 64-bit machines - if
they were, they'd zero the upper 32-bits. Maybe 64-bit machines are
happy with that anyway?

Rather than reimplementing the internals of pci_update_resource() it
may be worth splitting the common stuff out so it gets fixed for both
pci_update_resource() and pci_enable_device().

--
Russell King
Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/
maintainer of: 2.6 Serial core