'\" t
.\"     Title: pci_alloc_irq_vectors
.\"    Author: [FIXME: author] [see http://docbook.sf.net/el/author]
.\" Generator: DocBook XSL Stylesheets v1.79.1 <http://docbook.sf.net/>
.\"      Date: April 2019
.\"    Manual: Hardware Interfaces
.\"    Source: Kernel Hackers Manual 4.9.168
.\"  Language: English
.\"
.TH "PCI_ALLOC_IRQ_VECTOR" "9" "April 2019" "Kernel Hackers Manual 4\&.9\&." "Hardware Interfaces"
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.SH "NAME"
pci_alloc_irq_vectors \- allocate multiple IRQs for a device
.SH "SYNOPSIS"
.HP \w'int\ pci_alloc_irq_vectors('u
.BI "int pci_alloc_irq_vectors(struct\ pci_dev\ *\ " "dev" ", unsigned\ int\ " "min_vecs" ", unsigned\ int\ " "max_vecs" ", unsigned\ int\ " "flags" ");"
.SH "ARGUMENTS"
.PP
\fIdev\fR
.RS 4
PCI device to operate on
.RE
.PP
\fImin_vecs\fR
.RS 4
minimum number of vectors required (must be >= 1)
.RE
.PP
\fImax_vecs\fR
.RS 4
maximum (desired) number of vectors
.RE
.PP
\fIflags\fR
.RS 4
flags or quirks for the allocation
.RE
.SH "DESCRIPTION"
.PP
Allocate up to
\fImax_vecs\fR
interrupt vectors for
\fIdev\fR, 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
\fImax_vecs\fR) if successful, or a negative error code on error\&. If less than
\fImin_vecs\fR
interrupt vectors are available for
\fIdev\fR
the function will fail with \-ENOSPC\&.
.PP
To get the Linux IRQ number used for a vector that can be passed to
\fBrequest_irq\fR
use the
\fBpci_irq_vector\fR
helper\&.
.SH "COPYRIGHT"
.br