bnx2x: properly configure coefficients for MinBW algorithm (NPAR mode).

Signed-off-by: Dmitry Kravkov <dmitry@broadcom.com>
Signed-off-by: Eilon Greenstein <eilong@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 17 insertions, 12 deletions

diff --git a/drivers/net/bnx2x/bnx2x.h b/drivers/net/bnx2x/bnx2x.h
index 653c62475cb6..368cfcd0a211 100644
--- a/drivers/net/bnx2x/bnx2x.h
+++ b/drivers/net/bnx2x/bnx2x.h
@@ -1613,19 +1613,23 @@ static inline u32 reg_poll(struct bnx2x *bp, u32 reg, u32 expected, int ms,
 #define BNX2X_BTR                       4
 #define MAX_SPQ_PENDING                 8
 
-
-/* CMNG constants
-   derived from lab experiments, and not from system spec calculations !!! */
-#define DEF_MIN_RATE                    100
+/* CMNG constants, as derived from system spec calculations */
+/* default MIN rate in case VNIC min rate is configured to zero - 100Mbps */
+#define DEF_MIN_RATE                                    100
 /* resolution of the rate shaping timer - 100 usec */
-#define RS_PERIODIC_TIMEOUT_USEC        100
-/* resolution of fairness algorithm in usecs -
-   coefficient for calculating the actual t fair */
-#define T_FAIR_COEF                     10000000
+#define RS_PERIODIC_TIMEOUT_USEC                        100
 /* number of bytes in single QM arbitration cycle -
-   coefficient for calculating the fairness timer */
-#define QM_ARB_BYTES                    40000
-#define FAIR_MEM                        2
+ * coefficient for calculating the fairness timer */
+#define QM_ARB_BYTES                                    160000
+/* resolution of Min algorithm 1:100 */
+#define MIN_RES                                         100
+/* how many bytes above threshold for the minimal credit of Min algorithm*/
+#define MIN_ABOVE_THRESH                                32768
+/* Fairness algorithm integration time coefficient -
+ * for calculating the actual Tfair */
+#define T_FAIR_COEF     ((MIN_ABOVE_THRESH +  QM_ARB_BYTES) * 8 * MIN_RES)
+/* Memory of fairness algorithm . 2 cycles */
+#define FAIR_MEM                                        2
 
 
 #define ATTN_NIG_FOR_FUNC               (1L << 8)
diff --git a/drivers/net/bnx2x/bnx2x_main.c b/drivers/net/bnx2x/bnx2x_main.c
index 203e9bf65875..032ae184b605 100644
--- a/drivers/net/bnx2x/bnx2x_main.c
+++ b/drivers/net/bnx2x/bnx2x_main.c
@@ -2015,7 +2015,8 @@ static void bnx2x_init_vn_minmax(struct bnx2x *bp, int vn)
                 m_fair_vn.vn_credit_delta =
                         max_t(u32, (vn_min_rate * (T_FAIR_COEF /
                                                    (8 * bp->vn_weight_sum))),
-                              (bp->cmng.fair_vars.fair_threshold * 2));
+                              (bp->cmng.fair_vars.fair_threshold +
+                                                        MIN_ABOVE_THRESH));
                 DP(NETIF_MSG_IFUP, "m_fair_vn.vn_credit_delta %d\n",
                    m_fair_vn.vn_credit_delta);
         }