Re: [PATCH V2] powerpc/eeh: Fix kernel crash when passing through VF

On Fri, 2014-09-12 at 15:05 +1000, Gavin Shan wrote:

On Fri, Sep 12, 2014 at 01:55:23PM +1000, Michael Ellerman wrote:

quoted

On Thu, 2014-09-11 at 11:42 +0800, Wei Yang wrote:

quoted

diff --git a/arch/powerpc/kernel/eeh.c b/arch/powerpc/kernel/eeh.c
index 4a45ba8..403445e 100644
--- a/arch/powerpc/kernel/eeh.c
+++ b/arch/powerpc/kernel/eeh.c

@@ -625,7 +625,7 @@ int eeh_pci_enable(struct eeh_pe *pe, int function)
 int pcibios_set_pcie_reset_state(struct pci_dev *dev, enum pcie_reset_state state)
 {
 	struct eeh_dev *edev = pci_dev_to_eeh_dev(dev);
-	struct eeh_pe *pe = edev->pe;
+	struct eeh_pe *pe = edev ? edev->pe : NULL;
 
 	if (!pe) {
 		pr_err("%s: No PE found on PCI device %s\n",

We seem to do this or something similar in a few places. Is it worth having a
pci_dev_to_eeh_pe() inline?

Yes, maybe we just need a eeh_dev_to_pe() because converting
pci_dev to eeh_dev is already coverred by pci_dev_to_eeh_dev().

With eeh_dev_to_pe(), it looks like this:

struct pci_dev *pdev;
struct eeh_dev *edev = pci_dev_to_eeh_dev(pdev);
struct eeh_pe *pe = eeh_dev_to_pe(edev);

Or another case:

struct device_node *dn;
struct eeh_dev *edev = of_node_to_eeh_dev(dn);
struct eeh_pe *pe = eeh_dev_to_pe(edev);

Yeah I guess.

I saw a few places where we go from pci_dev to eeh_pe via a eeh_dev but then
don't use the eeh_dev at all. So for those it would make sense to have one
macro that does the full conversion from pci_dev to eeh_pe.

But if you think that's not very common then yeah a macro to do each stage is
fine.

cheers