On Wed, Jul 06, 2005 at 03:34:54AM +0400, Ivan Kokshaysky wrote: > On Tue, Jul 05, 2005 at 10:46:20PM +0100, Russell King wrote: > > On Tue, Jul 05, 2005 at 09:05:55PM +0100, Matthew Wilcox wrote: > > > 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? > > Why problematical? It's just the way how linux has always dealt with > 64-bit BARs - put everything below 4G in the bus address space, on *any* > architecture. I'd be quite surprised if some firmware doesn't do the same > thing - so far I haven't heard any complaints. If this is so, Grant's concern about programming the top half of 64-bit resources with zero isn't appropriate. However, he did raise this as an issue... -- Russell King Linux kernel 2.6 ARM Linux - http://www.arm.linux.org.uk/ maintainer of: 2.6 Serial core
