net/mlx5: Fix driver load with single msix vector

When a PCI device has just one msix vector available, we want to share
this vector between async and completion events. Current code fails to
do that assuming it will always have at least one dedicated vector for
completion events. Fix this by detecting when the pool contains just a
single vector.

Fixes: 3354822cde5a ("net/mlx5: Use dynamic msix vectors allocation")
Signed-off-by: Eli Cohen <elic@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Signed-off-by: Saeed Mahameed <saeedm@nvidia.com>

diff --git a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
index 843da89a903501dd8964bf5ba7de7967113fd5aa..33b9359de53d419f9d3e5f4d910b5df0d17d0fcc 100644 (file)
--- a/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
+++ b/drivers/net/ethernet/mellanox/mlx5/core/pci_irq.c
@@ -565,15 +565,21 @@ void mlx5_irqs_release_vectors(struct mlx5_irq **irqs, int nirqs)
 int mlx5_irqs_request_vectors(struct mlx5_core_dev *dev, u16 *cpus, int nirqs,
                              struct mlx5_irq **irqs, struct cpu_rmap **rmap)
 {
+       struct mlx5_irq_table *table = mlx5_irq_table_get(dev);
+       struct mlx5_irq_pool *pool = table->pcif_pool;
        struct irq_affinity_desc af_desc;
        struct mlx5_irq *irq;
+       int offset = 1;
        int i;
 
+       if (!pool->xa_num_irqs.max)
+               offset = 0;
+
        af_desc.is_managed = false;
        for (i = 0; i < nirqs; i++) {
                cpumask_clear(&af_desc.mask);
                cpumask_set_cpu(cpus[i], &af_desc.mask);
-               irq = mlx5_irq_request(dev, i + 1, &af_desc, rmap);
+               irq = mlx5_irq_request(dev, i + offset, &af_desc, rmap);
                if (IS_ERR(irq))
                        break;
                irqs[i] = irq;