[PATCH 6/9] PCI: Check IORESOURCE_UNSET before updating BAR

From: Bjorn Helgaas
Date: Wed Feb 26 2014 - 14:37:59 EST


Check to make sure we don't update a BAR with an address we haven't
assigned.

If we haven't assigned an address to a resource, we shouldn't write it to a
BAR. This isn't a problem for the usual path via pci_assign_resource(),
which clears IORESOURCE_UNSET before calling pci_update_resource(), but
paths like pci_restore_bars() can call this for resources we haven't
assigned.

Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
---
drivers/pci/setup-res.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 725d5b28398c..7f7652176fc5 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -44,6 +44,9 @@ void pci_update_resource(struct pci_dev *dev, int resno)
if (!res->flags)
return;

+ if (res->flags & IORESOURCE_UNSET)
+ return;
+
/*
* Ignore non-moveable resources. This might be legacy resources for
* which no functional BAR register exists or another important

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