Since commit c66d4bd110a1f8 ("genirq/affinity: Add new callback for
(re)calculating interrupt sets"), irq_create_affinity_masks() returns
NULL in case of single vector. This change has caused regression on some
drivers, such as lpfc.The problem is that single vector may be triggered in some generic cases: 1) kdump kernel 2) irq vectors resource is close to exhaustion. If we don't create affinity mask for single vector, almost every caller has to handle the special case. So still create affinity mask for single vector, since irq_create_affinity_masks() is capable of handling that. Cc: Marc Zyngier <[email protected]> Cc: Christoph Hellwig <[email protected]> Cc: Bjorn Helgaas <[email protected]> Cc: Jens Axboe <[email protected]> Cc: [email protected] Cc: Sagi Grimberg <[email protected]> Cc: [email protected] Cc: [email protected] Cc: Keith Busch <[email protected]> Cc: Sumit Saxena <[email protected]> Cc: Kashyap Desai <[email protected]> Cc: Shivasharan Srikanteshwara <[email protected]> Fixes: c66d4bd110a1f8 ("genirq/affinity: Add new callback for (re)calculating interrupt sets") Signed-off-by: Ming Lei <[email protected]> --- kernel/irq/affinity.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c index 4352b08ae48d..6fef48033f96 100644 --- a/kernel/irq/affinity.c +++ b/kernel/irq/affinity.c @@ -251,11 +251,9 @@ irq_create_affinity_masks(unsigned int nvecs, struct irq_affinity *affd) * Determine the number of vectors which need interrupt affinities * assigned. If the pre/post request exhausts the available vectors * then nothing to do here except for invoking the calc_sets() - * callback so the device driver can adjust to the situation. If there - * is only a single vector, then managing the queue is pointless as - * well. + * callback so the device driver can adjust to the situation. */ - if (nvecs > 1 && nvecs > affd->pre_vectors + affd->post_vectors) + if (nvecs > affd->pre_vectors + affd->post_vectors) affvecs = nvecs - affd->pre_vectors - affd->post_vectors; else affvecs = 0; -- 2.20.1
