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

Arnd Bergmann
2014-05-19T13:02:38Z

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