From: Dave Ertman <david.m.ertman@intel.com>
Date: Fri, 8 May 2020 00:41:01 +0000 (-0700)
Subject: ice: Fix check for contiguous TCs
X-Git-Tag: v5.8-rc1~165^2~140^2~12
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=891540024bb959c3ce8b71b851ba24cd3ad9423f;p=users%2Fwilly%2Fxarray.git

ice: Fix check for contiguous TCs

The current implementation for contiguous TC check
is assuming that the UPs will be mapped to TCs in
a linear progressing fashion.  This is obviously
not always true.

Change the check to allow for various UP2TC mapping
configurations.

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>
---

diff --git a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
index 448b7d2fb808..3c7f604c0c49 100644
--- a/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
+++ b/drivers/net/ethernet/intel/ice/ice_dcb_lib.c
@@ -584,16 +584,21 @@ static int ice_dcb_sw_dflt_cfg(struct ice_pf *pf, bool ets_willing, bool locked)
  */
 static bool ice_dcb_tc_contig(u8 *prio_table)
 {
-	u8 max_tc = 0;
+	bool found_empty = false;
+	u8 used_tc = 0;
 	int i;
 
-	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++) {
-		u8 cur_tc = prio_table[i];
+	/* Create a bitmap of used TCs */
+	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++)
+		used_tc |= BIT(prio_table[i]);
 
-		if (cur_tc > max_tc)
-			return false;
-		else if (cur_tc == max_tc)
-			max_tc++;
+	for (i = 0; i < CEE_DCBX_MAX_PRIO; i++) {
+		if (used_tc & BIT(i)) {
+			if (found_empty)
+				return false;
+		} else {
+			found_empty = true;
+		}
 	}
 
 	return true;