On Thu, Dec 05, 2013 at 01:44:53PM +0800, Jay Agarwal wrote:
> 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
Does your RC driver calls pci_assign_unassigned_resources after
pci_common_init?
Regards
Pratyush
> [ 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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