Date: Wed, 16 Jul 2008 10:35:13 -0700 From: "David Christensen" <davidch@broadcom.com> To: "freebsd-net@freebsd.org" <freebsd-net@freebsd.org> Subject: Enabling MSI-X on -CURRENT for New Network Driver Message-ID: <5D267A3F22FD854F8F48B3D2B52381932677F1A0C3@IRVEXCHCCR01.corp.ad.broadcom.com>
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I'm working on adding MSI-X support for a new network driver
and having some difficulty in actually getting an interrupt.
Does this look right?
/* Select and configure the IRQ. */
sc->bxe_msix_count =3D pci_msix_count(dev);
rid =3D 1;
/* Try allocating MSI-X interrupts. */
if ((sc->bxe_cap_flags & BXE_MSIX_CAPABLE_FLAG) &&
(bxe_msi_enable >=3D 2) && (sc->bxe_msix_count > 0)) {
int msix_needed =3D sc->bxe_msix_count;
if (pci_alloc_msix(dev, &sc->bxe_msix_count) =3D=3D 0) {
if (sc->bxe_msix_count =3D=3D msix_needed) {
DBPRINT(sc, BXE_INFO_LOAD, "%s(): Using %d =
MSI-X "
"vector(s).\n", __FUNCTION__, sc->b=
xe_msix_count);
sc->bxe_flags |=3D BXE_USING_MSIX_FLAG;
} else {
pci_release_msi(dev);
sc->bxe_flags &=3D ~BXE_USING_MSIX_FLAG;
sc->bxe_msix_count =3D 0;
}
}
}
/* Try allocating MSI interrupts if we didn't get MSI-X. */
...
/* Try legacy interrupt. */
...
/* Allocate the interrupt and report any errors. */
sc->bxe_res_irq =3D bus_alloc_resource_any(dev, SYS_RES_IRQ, &rid,
RF_ACTIVE);
/* Report any IRQ allocation errors. */
if (sc->bxe_res_irq =3D=3D NULL) {
BXE_PRINTF("%s(%d): PCI map interrupt failed!\n",
__FILE__, __LINE__);
rc =3D ENXIO;
goto bxe_attach_fail;
}
sc->bxe_irq_rid =3D rid;
sc->bxe_intr =3D bxe_intr;
The allocation doesn't fail and I usually see an IRQ allocated to
the driver using "vmstat -i" (though not always):
=3D=3D=3D[root] /usr/src/sys/modules/bxe # vmstat -i
interrupt total rate
irq1: atkbd0 1 0
irq4: sio0 46432 6
irq6: fdc0 10 0
irq14: ata0 58 0
irq17: atapci1 42684 5
cpu0: timer 15331063 1999
irq256: em0 917 0
cpu3: timer 15330811 1999
cpu1: timer 15330808 1999
cpu2: timer 15330811 1999
cpu5: timer 15330811 1999
cpu6: timer 15330810 1999
cpu4: timer 15330806 1999
cpu7: timer 15330811 1999
irq258: bxe0 2 0
Total 122736835 16010
But my interrupt handler doesn't seem to be called.
The goal is to get a single interrupt working first,
multiple queue support comes next. Any ideas?
Dave
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