pci_alloc_irq_vectors (9) Linux Manual Page
pci_alloc_irq_vectors – allocate multiple IRQs for a device
Synopsis
int pci_alloc_irq_vectors(struct pci_dev *dev, unsigned int min_vecs, unsigned int max_vecs, unsigned int flags);Arguments
dev
-
- PCI device to operate on
min_vecs
- minimum number of vectors required (must be >= 1)
max_vecs
- maximum (desired) number of vectors
flags
- flags or quirks for the allocation
Description
Allocate up to max_vecs interrupt vectors for dev, using MSI-X or MSI vectors if available, and fall back to a single legacy vector if neither is available. Return the number of vectors allocated, (which might be smaller than max_vecs) if successful, or a negative error code on error. If less than min_vecs interrupt vectors are available for dev the function will fail with -ENOSPC.
To get the Linux IRQ number used for a vector that can be passed to request_irq use the pci_irq_vector helper.