1 files changed, 25 insertions, 10 deletions

diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
index 81c99e1be708..c6ac7a61812f 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_main.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
@@ -4554,23 +4554,38 @@ static u8 i40e_get_iscsi_tc_map(struct i40e_pf *pf)
  **/
 static u8 i40e_dcb_get_num_tc(struct i40e_dcbx_config *dcbcfg)
 {
+        int i, tc_unused = 0;
         u8 num_tc = 0;
-        int i;
+        u8 ret = 0;
 
         /* Scan the ETS Config Priority Table to find
          * traffic class enabled for a given priority
-         * and use the traffic class index to get the
-         * number of traffic classes enabled
+         * and create a bitmask of enabled TCs
          */
-        for (i = 0; i < I40E_MAX_USER_PRIORITY; i++) {
-                if (dcbcfg->etscfg.prioritytable[i] > num_tc)
-                        num_tc = dcbcfg->etscfg.prioritytable[i];
-        }
+        for (i = 0; i < I40E_MAX_USER_PRIORITY; i++)
+                num_tc |= BIT(dcbcfg->etscfg.prioritytable[i]);
 
-        /* Traffic class index starts from zero so
-         * increment to return the actual count
+        /* Now scan the bitmask to check for
+         * contiguous TCs starting with TC0
          */
-        return num_tc + 1;
+        for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) {
+                if (num_tc & BIT(i)) {
+                        if (!tc_unused) {
+                                ret++;
+                        } else {
+                                pr_err("Non-contiguous TC - Disabling DCB\n");
+                                return 1;
+                        }
+                } else {
+                        tc_unused = 1;
+                }
+        }
+
+        /* There is always at least TC0 */
+        if (!ret)
+                ret = 1;
+
+        return ret;
 }
 
 /**