On 5/27/2015 12:54 PM, Lorenzo Pieralisi wrote:
diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> >index 062fee6..335d9f2 100644
> >--- a/drivers/pci/probe.c
> >+++ b/drivers/pci/probe.c
> >@@ -453,7 +453,11 @@ void pci_read_bridge_bases(struct pci_bus *child)
> > struct resource *res;
> > int i;
> >
> >- if (pci_is_root_bus(child)) /* It's a host bus, nothing to read */
> >+ /*
> >+ * If it is not a PCI bridge there is nothing to read
> >+ */
> >+ if (pci_is_root_bus(child) || !dev ||
> >+ !((dev->class >> 8) == PCI_CLASS_BRIDGE_PCI))
> > return;
> >
> > dev_info(&dev->dev, "PCI bridge to %pR%s\n",
> >@@ -1878,6 +1882,11 @@ unsigned int pci_scan_child_bus(struct pci_bus *bus)
> > * all PCI-to-PCI bridges on this bus.
> > */
> > if (!bus->is_added) {
> >+ /*
> >+ * Read and initialize bridge resources.
> >+ */
> >+ pci_read_bridge_bases(bus);
> >+
> > dev_dbg(&bus->dev, "fixups for bus\n");
> > pcibios_fixup_bus(bus);
> > bus->is_added = 1;
> >
>
>So, I have tested the patch on ARM64 system w/ PROBE_ONLY mode, and
>noticed that we are calling pci_read_bridge_bases() after adding the
>devices on the slots. This is not soon enough since the downstream
>devices still failing to claim resources.
>
>However, do you think we can move pci_read_bridge_bases() before the
>pci_scan_slot() loop?
Right, how about moving it to pci_scan_bridge() before calling the
respective pci_scan_child_bus() ? I think it belongs there anyway.
Thanks,
That seems reasonable. I test putting it here in pci_scan_bridge(),
and it works.
....
child = pci_find_bus(pci_domain_nr(bus), secondary);
if (!child) {
child = pci_add_new_bus(bus, dev, secondary);
if (!child)
goto out;
child->primary = primary;
pci_bus_insert_busn_res(child, secondary, subordinate);
child->bridge_ctl = bctl;
pci_read_bridge_bases(child);
}
cmax = pci_scan_child_bus(child);
.....
Thanks,
Suravee
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