[patch 2/19] pci: bridge resource handling update

Andrew Morton akpm at osdl.org
Sun Mar 20 18:55:35 EST 2005


Dominik Brodowski <linux at dominikbrodowski.net> wrote:
>
> "Transparent" PCI-PCI bridges are currently "ignored" by the resource
>  management code in the PCI core. This means devices behind the bridge are
>  handled as if there was no bridge.
> 
>  However, it seems more suitable -- and it seems to allow for proper
>  "prefetch"-type memory handling, too -- to handle a transparent PCI-PCI bridge
>  like any other PCI-PCI bridge, and to only break out of the limits set by
>  the bridge windows if the resource allocation code determines it needs to
>  do s.
> 
>  The tricky part is in pci_find_parent_resource(). There are two types of
>  functions calling it: some functions already know the exact resource for
>  which they want to find the parent in order to properly insert it into the
>  resource database. This can be handled easily -- if the resource is inside
>  the bridge window, this is returned; if it isn't, the bridge's parent
>  resource is returned.
> 
>  However, two callers (yenta_socket and i2o) intend something different: they
>  call pci_find_parent_resource() with an empty resource and want to find out
>  the biggest valid resource of the proper type in order to analyze it and
>  adapt its own hunger for resources to it. To keep this behaviour
>  backwards-compatible, we always need to not limit it to the bridge window
>  resources, but get back to the parent bus.
> 
> 
>  This patch is a modified and (hopefully) improved derivation of Linus'
>  "pcmcia-bridge-resource-management-fix.patch" included in 2.6.11-rc4-mm1.

I already had this in -mm, from you, titled
"pci-pci-transparent-bridge-handling-improvements-pci-core.patch.

It this patch something whcih should be pushed to Greg soonish, or is it
logically a part of the big pcmcia update?




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