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authorDave Ertman <david.m.ertman@intel.com>2016-08-12 09:56:32 -0700
committerJeff Kirsher <jeffrey.t.kirsher@intel.com>2016-08-16 13:23:13 -0700
commitfbfe12c64f9650aa22f434dd9dd22df7ddf63221 (patch)
treea12280873f34b4d3b72d350ae7fde0d9e1d95d79
parent3d951822be216d8c6fcfc8abf75e5ed307eeb646 (diff)
i40e: check for and deal with non-contiguous TCs
The i40e driver was causing a kernel panic when non-contiguous Traffic Classes, or Traffic Classes not starting with TC0, were configured on a link partner switch. i40e does not support non-contiguous TCs. To fix this, the patch changes the logic when determining the total number of TCs enabled. Before, this would use the highest TC number enabled and assume that all TCs below it were also enabled. Now, we create a bitmask of enabled TCs and scan it to determine not only the number of TCs, but also if the set of enabled TCs starts at zero and is contiguous. If not, then DCB is disabled by only returning one TC. Signed-off-by: Dave Ertman <david.m.ertman@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.c35
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;
}
/**