bnx2x: properly configure coefficients for MinBW algorithm (NPAR mode).
authorDmitry Kravkov <dmitry@broadcom.com>
Mon, 28 Feb 2011 03:37:11 +0000 (03:37 +0000)
committerDavid S. Miller <davem@davemloft.net>
Mon, 28 Feb 2011 21:14:48 +0000 (13:14 -0800)
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>
drivers/net/bnx2x/bnx2x.h
drivers/net/bnx2x/bnx2x_main.c

index 653c62475cb601582549a0abe63a4edf65fdfd68..368cfcd0a211012cd281c82aab765f8db68412ab 100644 (file)
@@ -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)
index 203e9bf658754fe30150e8e9f099212f22744fa7..032ae184b605dd0ebe67eb50a4bff6d723e66271 100644 (file)
@@ -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);
        }