pci_enable_msix throws up error

["Ravinandan Arakali" <ravinandan.arakali@neterion.com>]

Hi,
I am seeing the following problem with MSI/MSI-X.

Note: I am copying netdev since other network drivers use
this feature and somebody on the list could throw light.

Our 10G network card(Xframe II) supports MSI and MSI-X.
When I load/unload the driver with MSI support followed
by an attempt to load with MSI-X, I get the following
message from pci_enable_msix:

"Can't enable MSI-X.  Device already has an MSI vector assigned"

I seem to be doing the correct things when unloading the
MSI driver. Basically, I do free_irq() followed by pci_disable_msi().
Any idea what I am missing ?

Further analysis:
Looking at the code, the following check(when it finds a match) in
msi_lookup_vector(called by pci_enable_msix) seems to throw up this
message:
if (!msi_desc[vector] || msi_desc[vector]->dev != dev ||
    msi_desc[vector]->msi_attrib.type != type ||
    msi_desc[vector]->msi_attrib.default_vector != dev->irq)

pci_enable_msi, on successful completion will populate the
fields in msi_desc. But neither pci_disable_msi nor free_irq
seems to undo/unpopulate the msi_desc table.
Could this be the cause for the problem ?

Thanks,
Ravi


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