summaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMitch Williams <mitch.a.williams@intel.com>2017-12-18 11:15:25 +0100
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2018-01-23 20:29:19 +0100
commitb356dac8ab9e5e5954e550f2e2501b28511e90b8 (patch)
treeb88a09d8ddcff0b3c0b3d1933be1776d07aac101
parenti40e/i40evf: Enable NVMUpdate to retrieve AdminQ and add preservation flags f... (diff)
downloadlinux-b356dac8ab9e5e5954e550f2e2501b28511e90b8.tar.xz
linux-b356dac8ab9e5e5954e550f2e2501b28511e90b8.zip
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>
-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)