Generally, irq_create_affinity_masks() assign default affinity to pre/
post vectors correctly. However, it ignore the case that there are only
pre/post vectors (when nvecs == affd->pre_vectors + affd->post_vectors)
and return NULL. This case usually happens when nvecs = 1 (e.g. in nvme
driver when MSI-X is unavailable and fallback to MSI) and will trigger
the warning in pci_irq_get_affinity(). This patch fix the corner case.
Fixes: 6f9a22bc5775d231ab8f ("PCI/MSI: Ignore affinity if pre/post vector count is more than min_vecs")
Cc: stable@xxxxxxxxxxxxxxx
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Michael Hernandez <michael.hernandez@xxxxxxxxxx>
Signed-off-by: Huacai Chen <chenhc@xxxxxxxxxx>
---
kernel/irq/affinity.c | 18 +++++++++++-------
1 file changed, 11 insertions(+), 7 deletions(-)
diff --git a/kernel/irq/affinity.c b/kernel/irq/affinity.c
index 45b68b4..9b766eb 100644
--- a/kernel/irq/affinity.c
+++ b/kernel/irq/affinity.c
@@ -240,13 +240,6 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
struct irq_affinity_desc *masks = NULL;
int i, nr_sets;
- /*
- * If there aren't any vectors left after applying the pre/post
- * vectors don't bother with assigning affinity.
- */
- if (nvecs == affd->pre_vectors + affd->post_vectors)
- return NULL;
-
node_to_cpumask = alloc_node_to_cpumask();
if (!node_to_cpumask)
return NULL;
@@ -255,6 +248,17 @@ irq_create_affinity_masks(int nvecs, const struct irq_affinity *affd)
if (!masks)
goto outnodemsk;
+ /*
+ * If there aren't any vectors left after applying the pre/post
+ * vectors then just assign the default affinity to all vectors.
+ */
+ if (nvecs == affd->pre_vectors + affd->post_vectors) {
+ /* Fill all vectors that don't need affinity */
+ for (curvec = 0; curvec < nvecs; curvec++)
+ cpumask_copy(&masks[curvec].mask, irq_default_affinity);
+ goto outnodemsk;
+ }
+
/* Fill out vectors at the beginning that don't need affinity */
for (curvec = 0; curvec < affd->pre_vectors; curvec++)
cpumask_copy(&masks[curvec].mask, irq_default_affinity);
--
2.7.0
