Re: [PATCH v7 0/3] Add support for PCI in AArch64

[Arnd Bergmann <arnd@arndb.de>]

On Friday 16 May 2014 16:03:04 Sunil Kovvuri wrote:
> When the SR-IOV capable device's driver tries to enable sriov
> (pci_enable_sriov()) it fails to create/add PCI device for each
> virtual function reporting  "not enough MMIO resources for SR-IOV".

I assume you have checked that there is indeed enough MMIO space
available, right?

> In sriov_enable() (drivers/pci/iov.c)
> 
>  296        for (i = 0; i < PCI_SRIOV_NUM_BARS; i++) {
>  297                 bars |= (1 << (i + PCI_IOV_RESOURCES));
>  298                 res = dev->resource + PCI_IOV_RESOURCES + i;
>  299                 if (res->parent)
>  300                         nres++;
>  301         }
>  302         if (nres != iov->nres) {
>  303                 dev_err(&dev->dev, "not enough MMIO resources for
>  SR-IOV\n");
>  304                 return -ENOMEM;
>  305         }
> 
> Here its checking if physical function's IOV resource has a parent or not.
> Which is pci-pci bridge in this case. Otherwise it doesn't consider
> that resource.
> 
> Added below api to your patch.
> This will try to claim a resource while creating a PCI device which
> inturn sets 'res->parent'.

This looks like the wrong approach. The PCI host controller should
really have been registered with the root 'iomem_resource' during
the probe of the host controller.

	Arnd