This is a note to let you know that I've just added the patch titled net: stmmac: fix CBS idleslope and sendslope calculation to the 5.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-stmmac-fix-cbs-idleslope-and-sendslope-calculati.patch and it can be found in the queue-5.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit bab6325d64de5c2556f52f6699c652f0cfd4db9a Author: Song, Yoong Siang <yoong.siang.song@xxxxxxxxx> Date: Thu Feb 18 21:40:53 2021 +0800 net: stmmac: fix CBS idleslope and sendslope calculation [ Upstream commit 24877687b375f2c476ffb726ea915fc85df09e3d ] 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.song@xxxxxxxxx> Link: https://lore.kernel.org/r/1613655653-11755-1-git-send-email-yoong.siang.song@xxxxxxxxx Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c index 6088071cb1923..40dc14d1415f3 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_tc.c @@ -322,6 +322,32 @@ 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); @@ -338,10 +364,6 @@ 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);