On Wed, Feb 22, 2017 at 10:12:35PM -0800, Himanshu Madhani wrote:
> 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.
I don't think this is correct either. We'll need to move these checks
into __pci_enable_msix_range instead I think so that they operate
on the actual number of vectors not the min/max ones.
Something like the untested patch below, which will also need a MSI
version of the check, and possibly a bit of cleanup:
diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 7f73bacf13ed..6d11c4f620f3 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -1138,6 +1138,18 @@ static int __pci_enable_msix_range(struct pci_dev *dev,
for (;;) {
if (affd) {
+ if (affd->pre_vectors + affd->post_vectors > nvec)
+ 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 == nvec)
+ affd = NULL;
+ }
+ if (affd) {
nvec = irq_calc_affinity_vectors(nvec, affd);
if (nvec < minvec)
return -ENOSPC;
@@ -1206,16 +1218,6 @@ int pci_alloc_irq_vectors_affinity(struct pci_dev *dev, unsigned int min_vecs,
if (flags & PCI_IRQ_AFFINITY) {
if (!affd)
affd = &msi_default_affd;
-
- 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;
