Re: [PATCH] Resource: wrong resource window calculation

[Michal Ludvig <mludvig@logix.net.nz>]

On 09/22/2011 07:48 PM, Ram Pai wrote:
>    	Resource: wrong resource window calculation
>
> __find_resource() incorrectly returns a resource window which overlaps an
> existing allocated window. This happens when the parent's resource-window spans
> 0x00000000 to 0xffffffff and is entirely allocated to all its children
> resource-windows.
>
> __find_resource() looks for gaps in resource allocation among the children
> resource windows.  When it encounters the last child window it blindly tries
> the range next to one allocated to the last child. Since the last child's
> window ends at 0xffffffff the calculation overflows, leading the algorithm to
> believe that any window in the range 0x0000000 to 0xfffffff is available for
> allocation. This leads to a conflicting window allocation.
>
> Michal Ludvig reported this issue seen on his platform. The following patch
> fixes the problem and has been verified by Michal. I believe this bug has been
> there for ages. It got exposed by git commit
> 2bbc6942273b5b3097bd265d82227bdd84b351b2
> [PATCH] PCI : ability to relocate assigned pci-resources
>
> Signed-off-by: Ram Pai<linuxram@us.ibm.com>

Tested-by: Michal Ludvig <mludvig@logix.net.nz>

Works fine on top of 3.1.0-rc7 and solves the problem with my Jetway board.

Thanks Ram!

M.