During pci remove/rescan testing found:
[ 541.141614] pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
[ 541.141965] pci 0000:c0:03.0: bridge window [io 0x1000-0x0fff]
[ 541.159181] pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff]
[ 541.159540] pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
[ 541.179374] pci 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff])
[ 541.199198] pci 0000:c0:03.0: Error enabling bridge (-22), continuing
[ 541.199202] pci 0000:c0:03.0: enabling bus mastering
[ 541.199209] pci 0000:c0:03.0: setting latency timer to 64
[ 541.199917] pcieport 0000:c0:03.0: device not available (can't reserve [io 0x1000-0x0fff])
[ 541.199963] pcieport: probe of 0000:c0:03.0 failed with error -22
This bug was uncovered by commit
| commit c8adf9a3e873eddaaec11ac410a99ef6b9656938
| Author: Ram Pai <linuxram@xxxxxxxxxx>
| Date: Mon Feb 14 17:43:20 2011 -0800
|
| PCI: pre-allocate additional resources to devices only after successful allo
cation of essential resources.
After that commit, pci_hotplug_io_size is changed to additional_io_size from minium size. So it will not get into failed list, and will not be reset there.
The root cause is: pci_bridge_check_ranges will set RESOURCE_IO flag for pci
bridge, and later if children does not need to IO resource. those bridge
resources will not need to be allocated. but flags still there.
Add pci_bridge_check_resources() to close the loop.
after patch, will get right result:
[ 621.206655] pci 0000:c0:03.0: PCI bridge to [bus c4-c9]
[ 621.206912] pci 0000:c0:03.0: bridge window [io disabled]
[ 621.226594] pci 0000:c0:03.0: bridge window [mem 0xf0000000-0xf00fffff]
[ 621.226904] pci 0000:c0:03.0: bridge window [mem 0xfc180000000-0xfc197ffffff 64bit pref]
[ 621.247012] pci 0000:c0:03.0: enabling bus mastering
[ 621.247275] pci 0000:c0:03.0: setting latency timer to 64
[ 621.267656] pcieport 0000:c0:03.0: setting latency timer to 64
[ 621.268134] pcieport 0000:c0:03.0: irq 160 for MSI/MSI-X
[ 621.286832] pcieport 0000:c0:03.0: Signaling PME through PCIe PME interrupt
[ 621.306360] pci 0000:c4:00.0: Signaling PME through PCIe PME interrupt
[ 621.306684] pcie_pme 0000:c0:03.0:pcie01: service driver pcie_pme loaded
[ 621.326512] aer 0000:c0:03.0:pcie02: service driver aer loaded
[ 621.326911] pciehp 0000:c0:03.0:pcie04: Hotplug Controller:
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
---
drivers/pci/setup-bus.c | 26 ++++++++++++++++++++++++++
1 file changed, 26 insertions(+)
Index: linux-2.6/drivers/pci/setup-bus.c
===================================================================
--- linux-2.6.orig/drivers/pci/setup-bus.c
+++ linux-2.6/drivers/pci/setup-bus.c
@@ -811,6 +811,27 @@ void __ref pci_bus_size_bridges(struct p
}
EXPORT_SYMBOL(pci_bus_size_bridges);
+static void __ref pci_bridge_check_resources(struct pci_dev *bridge)
+{
+ struct resource *b_res;
+ int i;
+
+ b_res = &bridge->resource[PCI_BRIDGE_RESOURCES];
+
+ /*
+ * We set resource flag in pci_bridge_check_ranges() for further
+ * allocation for children devices.
+ * Then if children do not need some kind of resource (like IO), and
+ * bridge resource will not be allocated.
+ * At last, those flags could be left set, that will confuse
+ * pci_setup_bridge() and pci_enable_bridge()
+ * So use reset_resource to clear them.
+ */
+ for (i = 0; i < PCI_BRIDGE_RESOURCE_NUM; i++)
+ if (!resource_size(&b_res[i]))
+ reset_resource(&b_res[i]);
+}
+
static void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
struct resource_list_x *add_head,
struct resource_list_x *fail_head)
@@ -820,6 +841,9 @@ static void __ref __pci_bus_assign_resou
pbus_assign_resources_sorted(bus, add_head, fail_head);
+ if (bus->self)
+ pci_bridge_check_resources(bus->self);
+
list_for_each_entry(dev, &bus->devices, bus_list) {
b = dev->subordinate;
if (!b)
@@ -862,6 +886,8 @@ static void __ref __pci_bridge_assign_re
if (!b)
return;
+ pci_bridge_check_resources((struct pci_dev *)bridge);
+
__pci_bus_assign_resources(b, NULL, fail_head);
switch (bridge->class >> 8) {
--
To unsubscribe from this list: send the line "unsubscribe linux-pci" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
