| Message ID | 20171218101525.75683-1-alice.michael@intel.com |
|---|---|
| State | Accepted |
| Delegated to: | Jeff Kirsher |
| Headers | show |
| Series | [next,S83-V5,1/9] i40e/i40evf: Enable NVMUpdate to retrieve AdminQ and add preservation flags for NVM update | expand |
> -----Original Message----- > From: Intel-wired-lan [mailto:intel-wired-lan-bounces@osuosl.org] On > Behalf Of Alice Michael > Sent: Monday, December 18, 2017 2:15 AM > To: Michael, Alice <alice.michael@intel.com>; intel-wired- > lan@lists.osuosl.org > Subject: [Intel-wired-lan] [next PATCH S83-V5 2/9] i40e: avoid divide by zero > > From: Mitch Williams <mitch.a.williams@intel.com> > > 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> > --- > drivers/net/ethernet/intel/i40e/i40e_main.c | 9 +++++++-- > 1 file changed, 7 insertions(+), 2 deletions(-) Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c index 4f74156..7a882d7 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_main.c +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c @@ -10839,8 +10839,13 @@ 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)