--- /dev/null
+From b58fa682dceaee9e2576f9ba3f36942c650414ae Mon Sep 17 00:00:00 2001
+From: Ioana Radulescu <ruxandra.radulescu@nxp.com>
+Date: Tue, 17 Sep 2019 21:14:04 +0300
+Subject: [PATCH] dpaa2-eth: Keep congestion group taildrop enabled when PFC on
+
+Leave congestion group taildrop enabled for all traffic classes
+when PFC is enabled. Notification threshold is low enough such
+that it will be hit first and this also ensures that FQs on
+traffic classes which are not PFC enabled won't drain the buffer
+pool.
+
+FQ taildrop threshold is kept disabled as long as any form of
+flow control is on. Since FQ taildrop works with bytes, not number
+of frames, we can't guarantee it will not interfere with the
+congestion notification mechanism for all frame sizes.
+
+Signed-off-by: Ioana Radulescu <ruxandra.radulescu@nxp.com>
+---
+ drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c | 35 ++++++++++++++++++------
+ drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h | 4 ++-
+ 2 files changed, 30 insertions(+), 9 deletions(-)
+
+--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
++++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.c
+@@ -1229,17 +1229,21 @@ static void disable_ch_napi(struct dpaa2
+ }
+
+ static void dpaa2_eth_set_rx_taildrop(struct dpaa2_eth_priv *priv,
+- bool tx_pause)
++ bool tx_pause, bool pfc)
+ {
+ struct dpni_taildrop td = {0};
+ struct dpaa2_eth_fq *fq;
+ int i, err;
+
++ /* FQ taildrop: threshold is in bytes, per frame queue. Enabled if
++ * flow control is disabled (as it might interfere with either the
++ * buffer pool depletion trigger for pause frames or with the group
++ * congestion trigger for PFC frames)
++ */
+ td.enable = !tx_pause;
+- if (priv->rx_td_enabled == td.enable)
+- return;
++ if (priv->rx_fqtd_enabled == td.enable)
++ goto set_cgtd;
+
+- /* FQ taildrop: thrshold is in bytes, per frame queue */
+ td.threshold = DPAA2_ETH_FQ_TAILDROP_THRESH;
+ td.units = DPNI_CONGESTION_UNIT_BYTES;
+
+@@ -1257,9 +1261,20 @@ static void dpaa2_eth_set_rx_taildrop(st
+ }
+ }
+
++ priv->rx_fqtd_enabled = td.enable;
++
++set_cgtd:
+ /* Congestion group taildrop: threshold is in frames, per group
+ * of FQs belonging to the same traffic class
++ * Enabled if general Tx pause disabled or if PFCs are enabled
++ * (congestion group threhsold for PFC generation is lower than the
++ * CG taildrop threshold, so it won't interfere with it; we also
++ * want frames in non-PFC enabled traffic classes to be kept in check)
+ */
++ td.enable = !tx_pause || (tx_pause && pfc);
++ if (priv->rx_cgtd_enabled == td.enable)
++ return;
++
+ td.threshold = DPAA2_ETH_CG_TAILDROP_THRESH(priv);
+ td.units = DPNI_CONGESTION_UNIT_FRAMES;
+ for (i = 0; i < dpaa2_eth_tc_count(priv); i++) {
+@@ -1273,7 +1288,7 @@ static void dpaa2_eth_set_rx_taildrop(st
+ }
+ }
+
+- priv->rx_td_enabled = td.enable;
++ priv->rx_cgtd_enabled = td.enable;
+ }
+
+ static void update_tx_fqids(struct dpaa2_eth_priv *priv);
+@@ -1296,7 +1311,7 @@ static int link_state_update(struct dpaa
+ * only when pause frame generation is disabled.
+ */
+ tx_pause = dpaa2_eth_tx_pause_enabled(state.options);
+- dpaa2_eth_set_rx_taildrop(priv, tx_pause);
++ dpaa2_eth_set_rx_taildrop(priv, tx_pause, priv->pfc_enabled);
+
+ /* Chech link state; speed / duplex changes are not treated yet */
+ if (priv->link_state.up == state.up)
+@@ -3668,6 +3683,7 @@ static int dpaa2_eth_dcbnl_ieee_setpfc(s
+ {
+ struct dpaa2_eth_priv *priv = netdev_priv(net_dev);
+ struct dpni_link_cfg link_cfg = {0};
++ bool tx_pause;
+ int err;
+
+ if (pfc->mbc || pfc->delay)
+@@ -3680,8 +3696,8 @@ static int dpaa2_eth_dcbnl_ieee_setpfc(s
+ /* We allow PFC configuration even if it won't have any effect until
+ * general pause frames are enabled
+ */
+- if (!dpaa2_eth_rx_pause_enabled(priv->link_state.options) ||
+- !dpaa2_eth_tx_pause_enabled(priv->link_state.options))
++ tx_pause = dpaa2_eth_tx_pause_enabled(priv->link_state.options);
++ if (!dpaa2_eth_rx_pause_enabled(priv->link_state.options) || !tx_pause)
+ netdev_warn(net_dev, "Pause support must be enabled in order for PFC to work!\n");
+
+ link_cfg.rate = priv->link_state.rate;
+@@ -3702,6 +3718,9 @@ static int dpaa2_eth_dcbnl_ieee_setpfc(s
+ return err;
+
+ memcpy(&priv->pfc, pfc, sizeof(priv->pfc));
++ priv->pfc_enabled = !!pfc->pfc_en;
++
++ dpaa2_eth_set_rx_taildrop(priv, tx_pause, priv->pfc_enabled);
+
+ return 0;
+ }
+--- a/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
++++ b/drivers/net/ethernet/freescale/dpaa2/dpaa2-eth.h
+@@ -422,7 +422,8 @@ struct dpaa2_eth_priv {
+ struct dpaa2_eth_drv_stats __percpu *percpu_extras;
+
+ u16 mc_token;
+- u8 rx_td_enabled;
++ u8 rx_fqtd_enabled;
++ u8 rx_cgtd_enabled;
+
+ struct dpni_link_state link_state;
+ bool do_link_poll;
+@@ -434,6 +435,7 @@ struct dpaa2_eth_priv {
+ struct dpaa2_eth_cls_rule *cls_rules;
+ u8 rx_cls_enabled;
+ u8 vlan_cls_enabled;
++ u8 pfc_enabled;
+ #ifdef CONFIG_FSL_DPAA2_ETH_DCB
+ u8 dcbx_mode;
+ struct ieee_pfc pfc;
projects / openwrt / staging / wigyori.git / blobdiff