| From | Greg Kroah-Hartman <> | Subject | [PATCH 4.9 59/93] PCI: Ignore BAR updates on virtual functions | Date | Mon, 20 Mar 2017 18:51:34 +0100 |
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4.9-stable review patch. If anyone has any objections, please let me know.
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From: Bjorn Helgaas <bhelgaas@google.com>
[ Upstream commit 63880b230a4af502c56dde3d4588634c70c66006 ]
VF BARs are read-only zero, so updating VF BARs will not have any effect. See the SR-IOV spec r1.1, sec 3.4.1.11.
We already ignore these updates because of 70675e0b6a1a ("PCI: Don't try to restore VF BARs"); this merely restructures it slightly to make it easier to split updates for standard and SR-IOV BARs.
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> Reviewed-by: Gavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: Sasha Levin <alexander.levin@verizon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/pci/pci.c | 4 ---- drivers/pci/setup-res.c | 5 ++--- 2 files changed, 2 insertions(+), 7 deletions(-)
--- a/drivers/pci/pci.c +++ b/drivers/pci/pci.c @@ -564,10 +564,6 @@ static void pci_restore_bars(struct pci_ { int i; - /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */ - if (dev->is_virtfn) - return; - for (i = 0; i < PCI_BRIDGE_RESOURCES; i++) pci_update_resource(dev, i); } --- a/drivers/pci/setup-res.c +++ b/drivers/pci/setup-res.c @@ -34,10 +34,9 @@ static void pci_std_update_resource(stru int reg; struct resource *res = dev->resource + resno; - if (dev->is_virtfn) { - dev_warn(&dev->dev, "can't update VF BAR%d\n", resno); + /* Per SR-IOV spec 3.4.1.11, VF BARs are RO zero */ + if (dev->is_virtfn) return; - } /* * Ignore resources for unimplemented BARs and unused resource slots
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