From: Michael Hernandez <michael.hernandez@xxxxxxxxxx>
min_vecs is the minimum amount of vectors needed to operate in MSI-X mode
which may just include the vectors that don't need affinity.
Disabling affinity settings causes the qla2xxx driver scsi_add_host
to fail when blk_mq is enabled as the blk_mq_pci_map_queues expects
affinity masks on each vector.
v2 --> v3
o fixed code as per review comments.
v1 --> v2
o Moved the check from pci_alloc_irq_vectors_affinity() to
__pci_enable_{msi|msix}_range()
Fixes: dfef358 ("PCI/MSI: Don't apply affinity if there aren't enough vectors left")
Signed-off-by: Michael Hernandez <michael.hernandez@xxxxxxxxxx>
Signed-off-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
drivers/pci/msi.c | 25 ++++++++++++++++++-------
1 files changed, 18 insertions(+), 7 deletions(-)
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 7f73bac..46c0cdd 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1091,6 +1091,15 @@ static int __pci_enable_msi_range(struct pci_dev *dev, int minvec, int maxvec,
for (;;) {
if (affd) {
+ /*
+ * If there aren't any vectors left after applying the
+ * pre/post vectors don't bother with assigning
+ * affinity.
+ */
+ if (affd->pre_vectors + affd->post_vectors == nvec)
+ affd = NULL;
+ }
+ if (affd) {
nvec = irq_calc_affinity_vectors(nvec, affd);
if (nvec < minvec)
return -ENOSPC;
@@ -1138,6 +1147,15 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
for (;;) {
if (affd) {
+ /*
+ * If there aren't any vectors left after applying the
+ * pre/post vectors don't bother with assigning
+ * affinity.
+ */
+ if (affd->pre_vectors + affd->post_vectors == nvec)
+ affd = NULL;
+ }
+ if (affd) {
nvec = irq_calc_affinity_vectors(nvec, affd);
if (nvec < minvec)
return -ENOSPC;
@@ -1209,13 +1227,6 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
if (affd->pre_vectors + affd->post_vectors > min_vecs)
return -EINVAL;
-
- /*
- * If there aren't any vectors left after applying the pre/post
- * vectors don't bother with assigning affinity.
- */
- if (affd->pre_vectors + affd->post_vectors == min_vecs)
- affd = NULL;
} else {
if (WARN_ON(affd))
affd = NULL;
--
1.7.1
