Messages in this thread | | | From | Bjorn Helgaas <> | Date | Tue, 11 Sep 2012 17:35:11 -0600 | Subject | Re: [PATCH 1/1] pci-iov: Fix warnings when CONFIG_PCI_IOV is enabled |
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On Tue, Sep 4, 2012 at 5:11 PM, Jiang Wang <Jiang.Wang@riverbed.com> wrote: > When CONFIG_PCI_IOV is enabled, the kernel will call sriov_init(). > This function tries to allocate virtual resources even if the > virtual function of a PCI devive is not enabled by the BIOS. > > This sometimes causes following warning messages during boot up: > pci 0000:02:00.0: BAR 9: can't allocate mem resource [0x000000-0x3fffff] > pci 0000:02:00.0: BAR 7: can't allocate mem resource [0x000000-0x03ffff] > > Tested on three Mitac motherboards. > > Signed-off-by: Jiang Wang <jwang@riverbed.com> > --- > drivers/pci/iov.c | 3 ++- > 1 files changed, 2 insertions(+), 1 deletions(-) > > diff --git a/drivers/pci/iov.c b/drivers/pci/iov.c > index 6554e1a..0ca8cb2 100644 > --- a/drivers/pci/iov.c > +++ b/drivers/pci/iov.c > @@ -441,7 +441,8 @@ static int sriov_init(struct pci_dev *dev, int pos) > if (ctrl & PCI_SRIOV_CTRL_VFE) { > pci_write_config_word(dev, pos + PCI_SRIOV_CTRL, 0); > ssleep(1); > - } > + } else > + return 0;
But this would mean that Linux can't *ever* enable VFs unless the BIOS enabled them, right? I don't think that's what we want -- there's code in sriov_enable() to turn on VFE, assuming we have enough resources for the VFs.
It's certainly possible that the BIOS didn't allocate large enough apertures in the bridges leading to the SR-IOV device to accommodate all the VFs, and Linux may not be smart enough to enlarge them. And probably our warning messages in that case are not very enlightening.
Bjorn
> pci_read_config_word(dev, pos + PCI_SRIOV_TOTAL_VF, &total); > if (!total) > -- > 1.7.1 >
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