[PATCH net-next 5/5] net: dsa: mxl862xx: add SerDes ethtool statistics
From: Daniel Golle
Date: Tue May 19 2026 - 13:40:20 EST
Expose SerDes equalization and signal detect parameters as ethtool
statistics on ports 9-16 (XPCS-backed ports). Uses the XPCS EQ_GET
and SIGNAL_DETECT firmware commands to read TX/RX equalization
coefficients, DFE taps, and link-level signal status.
The 19 additional stats (serdes_tx_*, serdes_rx_*, serdes_pma_link,
serdes_link_fault, serdes_in_reset) are appended after the standard
RMON counters and gated on firmware >= 1.0.84.
Signed-off-by: Daniel Golle <daniel@xxxxxxxxxxxxxx>
---
drivers/net/dsa/mxl862xx/mxl862xx-api.h | 90 ++++++++++++++++++++
drivers/net/dsa/mxl862xx/mxl862xx-cmd.h | 2 +
drivers/net/dsa/mxl862xx/mxl862xx-phylink.c | 93 +++++++++++++++++++++
drivers/net/dsa/mxl862xx/mxl862xx-phylink.h | 3 +
drivers/net/dsa/mxl862xx/mxl862xx.c | 6 +-
5 files changed, 193 insertions(+), 1 deletion(-)
diff --git a/drivers/net/dsa/mxl862xx/mxl862xx-api.h b/drivers/net/dsa/mxl862xx/mxl862xx-api.h
index 6e332c99b245..4cd5d3f0b266 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx-api.h
+++ b/drivers/net/dsa/mxl862xx/mxl862xx-api.h
@@ -1668,4 +1668,94 @@ struct mxl862xx_xpcs_reset_cfg {
__le16 result;
} __packed;
+/**
+ * struct mxl862xx_xpcs_eq_item - single equalization parameter
+ * @value: current initial value
+ * @ovrd: override value
+ * @ovrd_en: override enable flag
+ */
+struct mxl862xx_xpcs_eq_item {
+ u8 value;
+ u8 ovrd;
+ u8 ovrd_en;
+} __packed;
+
+/**
+ * struct mxl862xx_xpcs_tx_eq_info - TX equalization status
+ * @main: TX main cursor (0-63)
+ * @pre: TX pre-cursor (0-63)
+ * @post: TX post-cursor (0-63)
+ * @iboost_lvl: TX iboost level (0-15)
+ * @vboost_lvl: TX vboost level (0-7)
+ * @vboost_en: TX vboost enable (0-1)
+ */
+struct mxl862xx_xpcs_tx_eq_info {
+ struct mxl862xx_xpcs_eq_item main;
+ struct mxl862xx_xpcs_eq_item pre;
+ struct mxl862xx_xpcs_eq_item post;
+ struct mxl862xx_xpcs_eq_item iboost_lvl;
+ struct mxl862xx_xpcs_eq_item vboost_lvl;
+ struct mxl862xx_xpcs_eq_item vboost_en;
+} __packed;
+
+/**
+ * struct mxl862xx_xpcs_rx_eq_info - RX equalization status
+ * @att_lvl: RX attenuation level (0-7)
+ * @vga1_gain: RX VGA1 gain (0-7)
+ * @vga2_gain: RX VGA2 gain (0-7)
+ * @ctle_boost: RX CTLE boost (0-31)
+ * @ctle_pole: RX CTLE pole (0-3)
+ * @dfe_tap1: RX DFE tap1 (0-255)
+ * @dfe_bypass: RX DFE bypass (0-1)
+ * @adapt_mode: RX adapt mode (0-3)
+ * @adapt_sel: RX adapt select (0-1)
+ */
+struct mxl862xx_xpcs_rx_eq_info {
+ struct mxl862xx_xpcs_eq_item att_lvl;
+ struct mxl862xx_xpcs_eq_item vga1_gain;
+ struct mxl862xx_xpcs_eq_item vga2_gain;
+ struct mxl862xx_xpcs_eq_item ctle_boost;
+ struct mxl862xx_xpcs_eq_item ctle_pole;
+ struct mxl862xx_xpcs_eq_item dfe_tap1;
+ struct mxl862xx_xpcs_eq_item dfe_bypass;
+ struct mxl862xx_xpcs_eq_item adapt_mode;
+ struct mxl862xx_xpcs_eq_item adapt_sel;
+} __packed;
+
+/**
+ * struct mxl862xx_xpcs_eq_get - EQ get request/response
+ * @port_id: XPCS port index (0 or 1)
+ * @result: firmware result
+ * @tx: TX equalization info
+ * @rx: RX equalization info
+ */
+struct mxl862xx_xpcs_eq_get {
+ u8 port_id;
+ __le16 result;
+ struct mxl862xx_xpcs_tx_eq_info tx;
+ struct mxl862xx_xpcs_rx_eq_info rx;
+} __packed;
+
+/**
+ * struct mxl862xx_xpcs_signal_detect - signal detect status
+ * @port_id: XPCS port index (0 or 1)
+ * @rx_signal: RX signal detected
+ * @pma_link: PMA link up
+ * @link_fault: PCS link fault
+ * @in_reset: XPCS in reset
+ * @__rsv: reserved
+ * @__pad: padding
+ * @result: firmware result
+ */
+struct mxl862xx_xpcs_signal_detect {
+ u8 port_id:2;
+ u8 rx_signal:1;
+ u8 pma_link:1;
+ u8 link_fault:1;
+ u8 in_reset:1;
+ u8 __rsv:2;
+ u8 __pad;
+ __le16 result;
+} __packed;
+
#endif /* __MXL862XX_API_H */
diff --git a/drivers/net/dsa/mxl862xx/mxl862xx-cmd.h b/drivers/net/dsa/mxl862xx/mxl862xx-cmd.h
index c87a955c13c4..f6fa32bac5d8 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx-cmd.h
+++ b/drivers/net/dsa/mxl862xx/mxl862xx-cmd.h
@@ -79,6 +79,8 @@
#define MXL862XX_XPCS_PCS_LINK_UP (MXL862XX_XPCS_MAGIC + 0x7)
#define MXL862XX_XPCS_LOOPBACK (MXL862XX_XPCS_MAGIC + 0x8)
#define MXL862XX_XPCS_RESET (MXL862XX_XPCS_MAGIC + 0x9)
+#define MXL862XX_XPCS_EQ_GET (MXL862XX_XPCS_MAGIC + 0xc)
+#define MXL862XX_XPCS_SIGNAL_DETECT (MXL862XX_XPCS_MAGIC + 0xd)
#define MMD_API_MAXIMUM_ID 0x7fff
diff --git a/drivers/net/dsa/mxl862xx/mxl862xx-phylink.c b/drivers/net/dsa/mxl862xx/mxl862xx-phylink.c
index f99c69984357..c5ee07a444e9 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx-phylink.c
+++ b/drivers/net/dsa/mxl862xx/mxl862xx-phylink.c
@@ -351,3 +351,96 @@ const struct phylink_mac_ops mxl862xx_phylink_mac_ops = {
.mac_link_up = mxl862xx_phylink_mac_link_up,
.mac_select_pcs = mxl862xx_phylink_mac_select_pcs,
};
+
+/* --- SerDes ethtool statistics --- */
+
+static const char mxl862xx_serdes_stats[][ETH_GSTRING_LEN] = {
+ "serdes_tx_main",
+ "serdes_tx_pre",
+ "serdes_tx_post",
+ "serdes_tx_iboost",
+ "serdes_tx_vboost",
+ "serdes_tx_vboost_en",
+ "serdes_rx_att",
+ "serdes_rx_vga1",
+ "serdes_rx_vga2",
+ "serdes_rx_ctle_boost",
+ "serdes_rx_ctle_pole",
+ "serdes_rx_dfe_tap1",
+ "serdes_rx_dfe_bypass",
+ "serdes_rx_adapt_mode",
+ "serdes_rx_adapt_sel",
+ "serdes_rx_signal",
+ "serdes_pma_link",
+ "serdes_link_fault",
+ "serdes_in_reset",
+};
+
+static bool mxl862xx_port_has_serdes_stats(struct dsa_switch *ds, int port)
+{
+ struct mxl862xx_priv *priv = ds->priv;
+
+ return port >= 9 && port <= 16 &&
+ MXL862XX_FW_VER_MIN(priv, 1, 0, 84);
+}
+
+int mxl862xx_serdes_stats_count(struct dsa_switch *ds, int port)
+{
+ if (mxl862xx_port_has_serdes_stats(ds, port))
+ return ARRAY_SIZE(mxl862xx_serdes_stats);
+
+ return 0;
+}
+
+void mxl862xx_serdes_get_strings(struct dsa_switch *ds, int port, u8 *data)
+{
+ int i;
+
+ if (!mxl862xx_port_has_serdes_stats(ds, port))
+ return;
+
+ for (i = 0; i < ARRAY_SIZE(mxl862xx_serdes_stats); i++)
+ ethtool_puts(&data, mxl862xx_serdes_stats[i]);
+}
+
+void mxl862xx_serdes_get_stats(struct dsa_switch *ds, int port, u64 *data)
+{
+ struct mxl862xx_xpcs_eq_get eq = {
+ .port_id = MXL862XX_SERDES_PORT_ID(port),
+ };
+ struct mxl862xx_xpcs_signal_detect sig = {};
+
+ if (!mxl862xx_port_has_serdes_stats(ds, port))
+ return;
+
+ sig.port_id = MXL862XX_SERDES_PORT_ID(port);
+
+ if (!MXL862XX_API_READ(ds->priv, MXL862XX_XPCS_EQ_GET, eq)) {
+ *data++ = eq.tx.main.value;
+ *data++ = eq.tx.pre.value;
+ *data++ = eq.tx.post.value;
+ *data++ = eq.tx.iboost_lvl.value;
+ *data++ = eq.tx.vboost_lvl.value;
+ *data++ = eq.tx.vboost_en.value;
+ *data++ = eq.rx.att_lvl.value;
+ *data++ = eq.rx.vga1_gain.value;
+ *data++ = eq.rx.vga2_gain.value;
+ *data++ = eq.rx.ctle_boost.value;
+ *data++ = eq.rx.ctle_pole.value;
+ *data++ = eq.rx.dfe_tap1.value;
+ *data++ = eq.rx.dfe_bypass.value;
+ *data++ = eq.rx.adapt_mode.value;
+ *data++ = eq.rx.adapt_sel.value;
+ } else {
+ data += 15;
+ }
+
+ if (!MXL862XX_API_READ(ds->priv, MXL862XX_XPCS_SIGNAL_DETECT, sig)) {
+ *data++ = sig.rx_signal;
+ *data++ = sig.pma_link;
+ *data++ = sig.link_fault;
+ *data++ = sig.in_reset;
+ } else {
+ data += 4;
+ }
+}
diff --git a/drivers/net/dsa/mxl862xx/mxl862xx-phylink.h b/drivers/net/dsa/mxl862xx/mxl862xx-phylink.h
index 54a4c652ec5a..82cc3817adc1 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx-phylink.h
+++ b/drivers/net/dsa/mxl862xx/mxl862xx-phylink.h
@@ -20,5 +20,8 @@ void mxl862xx_phylink_get_caps(struct dsa_switch *ds, int port,
struct phylink_config *config);
void mxl862xx_setup_pcs(struct mxl862xx_priv *priv, struct mxl862xx_pcs *pcs,
int port);
+int mxl862xx_serdes_stats_count(struct dsa_switch *ds, int port);
+void mxl862xx_serdes_get_strings(struct dsa_switch *ds, int port, u8 *data);
+void mxl862xx_serdes_get_stats(struct dsa_switch *ds, int port, u64 *data);
#endif /* __MXL862XX_PHYLINK_H */
diff --git a/drivers/net/dsa/mxl862xx/mxl862xx.c b/drivers/net/dsa/mxl862xx/mxl862xx.c
index 0af41efccbc6..a18e42b9cd6b 100644
--- a/drivers/net/dsa/mxl862xx/mxl862xx.c
+++ b/drivers/net/dsa/mxl862xx/mxl862xx.c
@@ -1776,6 +1776,8 @@ static void mxl862xx_get_strings(struct dsa_switch *ds, int port,
for (i = 0; i < ARRAY_SIZE(mxl862xx_mib); i++)
ethtool_puts(&data, mxl862xx_mib[i].name);
+
+ mxl862xx_serdes_get_strings(ds, port, data);
}
static int mxl862xx_get_sset_count(struct dsa_switch *ds, int port, int sset)
@@ -1783,7 +1785,7 @@ static int mxl862xx_get_sset_count(struct dsa_switch *ds, int port, int sset)
if (sset != ETH_SS_STATS)
return 0;
- return ARRAY_SIZE(mxl862xx_mib);
+ return ARRAY_SIZE(mxl862xx_mib) + mxl862xx_serdes_stats_count(ds, port);
}
static int mxl862xx_read_rmon(struct dsa_switch *ds, int port,
@@ -1819,6 +1821,8 @@ static void mxl862xx_get_ethtool_stats(struct dsa_switch *ds, int port,
else
*data++ = le64_to_cpu(*(__le64 *)field);
}
+
+ mxl862xx_serdes_get_stats(ds, port, data);
}
static void mxl862xx_get_eth_mac_stats(struct dsa_switch *ds, int port,
--
2.54.0