[PATCH net 1/1] net: stmmac: fix CBS idleslope and sendslope calculation

[Song Yoong Siang]

From: "Song, Yoong Siang" <yoong.siang.s...@intel.com>

When link speed is not 100 Mbps, port transmit rate and speed divider
are set to 8 and 1000000 respectively. These values are incorrect for
CBS idleslope and sendslope HW values calculation if the link speed is
not 1 Gbps.

This patch adds switch statement to set the values of port transmit rate
and speed divider for 10 Gbps, 5 Gbps, 2.5 Gbps, 1 Gbps, and 100 Mbps.
Note that CBS is not supported at 10 Mbps.

Fixes: bc41a6689b30 ("net: stmmac: tc: Remove the speed dependency")
Fixes: 1f705bc61aee ("net: stmmac: Add support for CBS QDISC")
Signed-off-by: Song, Yoong Siang <yoong.siang.s...@intel.com>
---
 drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c | 30 +++++++++++++++++++++----
 1 file changed, 26 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c 
b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
index 5698554..44bb133 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c
@@ -316,6 +316,32 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
        if (!priv->dma_cap.av)
                return -EOPNOTSUPP;
 
+       /* Port Transmit Rate and Speed Divider */
+       switch (priv->speed) {
+       case SPEED_10000:
+               ptr = 32;
+               speed_div = 10000000;
+               break;
+       case SPEED_5000:
+               ptr = 32;
+               speed_div = 5000000;
+               break;
+       case SPEED_2500:
+               ptr = 8;
+               speed_div = 2500000;
+               break;
+       case SPEED_1000:
+               ptr = 8;
+               speed_div = 1000000;
+               break;
+       case SPEED_100:
+               ptr = 4;
+               speed_div = 100000;
+               break;
+       default:
+               return -EOPNOTSUPP;
+       }
+
        mode_to_use = priv->plat->tx_queues_cfg[queue].mode_to_use;
        if (mode_to_use == MTL_QUEUE_DCB && qopt->enable) {
                ret = stmmac_dma_qmode(priv, priv->ioaddr, queue, 
MTL_QUEUE_AVB);
@@ -332,10 +358,6 @@ static int tc_setup_cbs(struct stmmac_priv *priv,
                priv->plat->tx_queues_cfg[queue].mode_to_use = MTL_QUEUE_DCB;
        }
 
-       /* Port Transmit Rate and Speed Divider */
-       ptr = (priv->speed == SPEED_100) ? 4 : 8;
-       speed_div = (priv->speed == SPEED_100) ? 100000 : 1000000;
-
        /* Final adjustments for HW */
        value = div_s64(qopt->idleslope * 1024ll * ptr, speed_div);
        priv->plat->tx_queues_cfg[queue].idle_slope = value & GENMASK(31, 0);
-- 
2.7.4