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authorMitch Williams <mitch.a.williams@intel.com>2017-12-18 05:15:25 -0500
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2018-01-23 11:29:19 -0800
commitb356dac8ab9e5e5954e550f2e2501b28511e90b8 (patch)
treeb88a09d8ddcff0b3c0b3d1933be1776d07aac101 /drivers/net
parente3a5d6e6fa8aae99f12f181597d065ae2ecf768d (diff)
i40e: avoid divide by zero
In some weird circumstances with DCB enabled, the firmware can fail to configure the VSI, leaving us with zero traffic classes. Check for this state when we configure RSS to avoid a panic. 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>
Diffstat (limited to 'drivers/net')
-rw-r--r--drivers/net/ethernet/intel/i40e/i40e_main.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index e29d42c67fa9..db7dd812c1df 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -10783,8 +10783,13 @@ static int i40e_pf_config_rss(struct i40e_pf *pf)
/* Determine the RSS size of the VSI */
if (!vsi->rss_size) {
u16 qcount;
-
- qcount = vsi->num_queue_pairs / vsi->tc_config.numtc;
+ /* If the firmware does something weird during VSI init, we
+ * could end up with zero TCs. Check for that to avoid
+ * divide-by-zero. It probably won't pass traffic, but it also
+ * won't panic.
+ */
+ qcount = vsi->num_queue_pairs /
+ (vsi->tc_config.numtc ? vsi->tc_config.numtc : 1);
vsi->rss_size = min_t(int, pf->alloc_rss_size, qcount);
}
if (!vsi->rss_size)