When debugging an issue where I was asking the PCI machinery to enable a set of MSI-X vectors, without falling back on MSI, I ran across a behaviour which seems odd. The pci_alloc_irq_vectors_affinity() will always return -ENOSPC on failure, when allocating MSI-X vectors only, whereas with MSI fallback it will forward any error returned by __pci_enable_msi_range(). This is a confusing behaviour, so have the pci_alloc_irq_vectors_affinity() forward the error code from __pci_enable_msix_range() when appropriate. Signed-off-by: Piotr Stankiewicz <piotr.stankiewicz@xxxxxxxxx> Reviewed-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxx> --- drivers/pci/msi.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 6b43a5455c7a..443cc324b196 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1231,8 +1231,9 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } } - if (msix_vecs == -ENOSPC) - return -ENOSPC; + if (msix_vecs == -ENOSPC || + (flags & (PCI_IRQ_MSI | PCI_IRQ_MSIX)) == PCI_IRQ_MSIX) + return msix_vecs; return msi_vecs; } EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity); -- 2.17.2
