On Mon, May 19, 2014 at 6:31 PM, Arnd Bergmann arnd@arndb.de wrote:
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?
Yes, i have checked for enough MMIO space multiple times.
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
I didn't get this, if a SR-IOV device is connected to a PCI-PCI bridge and inturn bridge connected to root port. Then the parent bus is not root, but the bridge. The issue is either hierarchy should not be checked for SR-IOV resources or someone should set the hierarchy (i.e parent resources).
Regards, Sunil.