i40e: don't configure zero-size RSS table

In some rare cases, we might get a VSI with no queues. In this case, we
cannot configure RSS on this VSI as it will try to divide by zero when
configuring the lookup table.

Change-ID: I6ae173a7dd3481a081e079eb10eb80275de2adb0
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index b434d07..8176596 100644 (file)
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -8282,6 +8282,8 @@ static int i40e_pf_config_rss(struct i40e_pf *pf)
        if (!vsi->rss_size)
                vsi->rss_size = min_t(int, pf->alloc_rss_size,
                                      vsi->num_queue_pairs);
+       if (!vsi->rss_size)
+               return -EINVAL;
 
        lut = kzalloc(vsi->rss_table_size, GFP_KERNEL);
        if (!lut)