| title: | Re PATCH v3 05 11 PCI beef up pci do scan |
|
Hello Kenji-san,
* Kenji Kaneshige <kaneshige.kenji@xxxxxxxxxxxxxx :
Alex Chiang wrote:
We have a nice interface for re-scanning a PCI bus which will
discover newly added devices, add them to the device tree, and
enable them properly.
Ensure that the bridge resources are properly sized and assigned
during the rescan.
Signed-off-by: Alex Chiang <achiang@xxxxxx
---
drivers/pci/hotplug-pci.c | 16 ++++++++++++----
1 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/pci/hotplug-pci.c b/drivers/pci/hotplug-pci.c
index 4d4a644..33ab2d2 100644
--- a/drivers/pci/hotplug-pci.c
+++ b/drivers/pci/hotplug-pci.c
@@ -6,13 +6,21 @@
unsigned int __devinit pci_do_scan_bus(struct pci_bus *bus)
{
- unsigned int max;
+ unsigned int max, pass;
+ struct pci_dev *dev;
max = pci_scan_child_bus(bus);
- /*
- * Make the discovered devices available.
- */
+ for (pass=0; pass < 2; pass++)
+ list_for_each_entry(dev, &bus- devices, bus_list) {
+ if (dev- hdr_type == PCI_HEADER_TYPE_BRIDGE ||
+ dev- hdr_type == PCI_HEADER_TYPE_CARDBUS)
+ if (pass && dev- subordinate)
+ pci_bus_size_bridges(dev- subordinate);
+ }
+
+ pci_bus_assign_resources(bus);
+ pci_enable_bridges(bus);
pci_bus_add_devices(bus);
The "for (pass=0; pass <2; pass++)" loop doesnt look necessary.
Yes, I dont know why I had it in there originally. I can remove
that.
And Im worrying that your change have some bad effect to the
existing user of pci_do_scan_bus(). Did you confirm that?
I hadnt gotten around to verifying/fixing existing callers of
pci_do_scan_bus yet. I was focusing on the core first.
There arent too many callers, but unfortunately, I dont have
any hardware that actually uses the existing drivers.
I seem to recall that your machines support shpchp. Would you
mind testing this patch and telling me if your machine still
behaves properly?
I looked at shpchp_configure_device and I think that simply
scanning the devices parent bus should work.
Thanks.
/ac
diff --git a/drivers/pci/hotplug/shpchp_pci.c b/drivers/pci/hotplug/shpchp_pci.c
index aa315e5..7e8457b 100644
--- a/drivers/pci/hotplug/shpchp_pci.c
+++ b/drivers/pci/hotplug/shpchp_pci.c
@@ -110,11 +110,7 @@ int __ref shpchp_configure_device(struct slot *p_slot)
return -EINVAL;
}
- num = pci_scan_slot(parent, PCI_DEVFN(p_slot- device, 0));
- if (num == 0) {
- ctrl_err(ctrl, "No new device found
");
- return -ENODEV;
- }
+ pci_do_scan_bus(parent);
for (fn = 0; fn < 8; fn++) {
dev = pci_get_slot(parent, PCI_DEVFN(p_slot- device, fn));
@@ -126,40 +122,10 @@ int __ref shpchp_configure_device(struct slot *p_slot)
pci_dev_put(dev);
continue;
}
- if ((dev- hdr_type == PCI_HEADER_TYPE_BRIDGE) ||
- (dev- hdr_type == PCI_HEADER_TYPE_CARDBUS)) {
- /* Find an unused bus number for the new bridge */
- struct pci_bus *child;
- unsigned char busnr, start = parent- secondary;
- unsigned char end = parent- subordinate;
- for (busnr = start; busnr <= end; busnr++) {
- if (!pci_find_bus(pci_domain_nr(parent),
- busnr))
- break;
- }
- if (busnr end) {
- ctrl_err(ctrl,
- "No free bus for hot-added bridge
");
- pci_dev_put(dev);
- continue;
- }
- child = pci_add_new_bus(parent, dev, busnr);
- if (!child) {
- ctrl_err(ctrl, "Cannot add new bus for %s
",
- pci_name(dev));
- pci_dev_put(dev);
- continue;
- }
- child- subordinate = pci_do_scan_bus(child);
- pci_bus_size_bridges(child);
- }
program_fw_provided_values(dev);
pci_dev_put(dev);
}
- pci_bus_assign_resources(parent);
- pci_bus_add_devices(parent);
- pci_enable_bridges(parent);
return 0;
}
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