Hi All,
I am seeing below issue on an ARM platform with CONFIG_PCIEPORTBUS enabled in kernel
ISSUE: Any memory access by devices fails
FINDINGS:
1. No bridge windows like below are setup and probably this is not allowing any memory access by devices
[ 1.280324] pci 0000:00:00.0: bridge window [mem 0xXXX00000-0xXXXfffff]
[ 1.280350] pci 0000:00:00.0: bridge window [mem 0xXXX00000-0xXXXfffff pref]
2. On debugging, I see pci_enable_bridge(setup-bus.c) is not called because pci_is_enabled returns true. This is because pci_enable_device is already called for this bridge by portbus driver in pcie_port_device_register(portdrv_core.c).
3. Below patch is resolving this issue without any visible side effects. In fact, I verified AER(which needs PORTBUS) also with this.
diff --git a/drivers/pci/setup-bus.c b/drivers/pci/setup-bus.c index 64a7de2..9b67fff 100644
--- a/drivers/pci/setup-bus.c
+++ b/drivers/pci/setup-bus.c
@@ -1200,8 +1200,7 @@ void __ref __pci_bus_assign_resources(const struct pci_bus *bus,
switch (dev->class >> 8) {
case PCI_CLASS_BRIDGE_PCI:
- if (!pci_is_enabled(dev))
- pci_setup_bridge(b);
+ pci_setup_bridge(b);
break;
case PCI_CLASS_BRIDGE_CARDBUS:
3. This patch works without PORTBUS enabled also.
QUESTIONS:
1. Does anybody see any problem with this patch? Any reason for pci_is_enabled check above?
With best,
Jay
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