Message ID | 20200609091440.497-1-piotr.stankiewicz@intel.com (mailing list archive) |
---|---|
State | Superseded, archived |
Headers | show |
Series | [v3,01/15] PCI/MSI: Forward MSI-X vector enable error code in pci_alloc_irq_vectors_affinity() | expand |
On 2020-06-09 3:14 a.m., Piotr Stankiewicz wrote: > 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@intel.com> Looks fine to me: Reviewed-by: Logan Gunthorpe <logang@deltatee.com> Thanks! > --- > 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); > >
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
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);
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@intel.com> --- drivers/pci/msi.c | 22 +++++++++------------- 1 file changed, 9 insertions(+), 13 deletions(-)