Re: [PATCH v10 4/4] PCI: Allow extend_bridge_window() to shrink resource if necessary

From: Nicholas Johnson
Date: Wed Oct 30 2019 - 09:33:34 EST


On Wed, Oct 30, 2019 at 03:25:09PM +0200, mika.westerberg@xxxxxxxxxxxxxxx wrote:
> On Wed, Oct 30, 2019 at 12:47:44PM +0000, Nicholas Johnson wrote:
> > Remove checks for resource size in extend_bridge_window(). This is
> > necessary to allow the pci_bus_distribute_available_resources() to
> > function when the kernel parameter pci=hpmemsize=nn[KMG] is used to
> > allocate resources. Because the kernel parameter sets the size of all
> > hotplug bridges to be the same, there are problems when nested hotplug
> > bridges are encountered. Fitting a downstream hotplug bridge with size X
> > and normal bridges with non-zero size Y into parent hotplug bridge with
> > size X is impossible, and hence the downstream hotplug bridge needs to
> > shrink to fit into its parent.
> >
> > Add check for if bridge is extended or shrunken and adjust pci_dbg to
> > reflect this.
> >
> > Reset the resource if its new size is zero (if we have run out of a
> > bridge window resource) to prevent the PCI resource assignment code from
> > attempting to assign a zero-sized resource.
> >
> > Rename extend_bridge_window() to adjust_bridge_window() to reflect the
> > fact that the window can now shrink.
> >
> > Signed-off-by: Nicholas Johnson <nicholas.johnson-opensource@xxxxxxxxxxxxxx>
>
> Reviewed-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Do I need to re-post with this line in it?

Cheers!