From 30ff3e8c287455e9f7f85162df10d62819ba42a9 Mon Sep 17 00:00:00 2001 From: Piotr Stankiewicz Date: Tue, 16 Jun 2020 09:33:16 +0200 Subject: [PATCH] PCI/MSI: Forward MSI-X error code in pci_alloc_irq_vectors_affinity() 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. Link: https://lore.kernel.org/r/20200616073318.20229-1-piotr.stankiewicz@intel.com Signed-off-by: Piotr Stankiewicz Signed-off-by: Bjorn Helgaas Reviewed-by: Andy Shevchenko Reviewed-by: Logan Gunthorpe Reviewed-by: Christoph Hellwig --- drivers/pci/msi.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-) diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 6b43a5455c7a..cade9be68b09 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -1191,8 +1191,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, struct irq_affinity *affd) { struct irq_affinity msi_default_affd = {0}; - int msix_vecs = -ENOSPC; - int msi_vecs = -ENOSPC; + int nvecs = -ENOSPC; if (flags & PCI_IRQ_AFFINITY) { if (!affd) @@ -1203,17 +1202,16 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } if (flags & PCI_IRQ_MSIX) { - msix_vecs = __pci_enable_msix_range(dev, NULL, min_vecs, - max_vecs, affd, flags); - if (msix_vecs > 0) - return msix_vecs; + nvecs = __pci_enable_msix_range(dev, NULL, min_vecs, max_vecs, + affd, flags); + if (nvecs > 0) + return nvecs; } if (flags & PCI_IRQ_MSI) { - msi_vecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, - affd); - if (msi_vecs > 0) - return msi_vecs; + nvecs = __pci_enable_msi_range(dev, min_vecs, max_vecs, affd); + if (nvecs > 0) + return nvecs; } /* use legacy IRQ if allowed */ @@ -1231,9 +1229,7 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs, } } - if (msix_vecs == -ENOSPC) - return -ENOSPC; - return msi_vecs; + return nvecs; } EXPORT_SYMBOL(pci_alloc_irq_vectors_affinity);