[PATCH net-next v2] net: stmmac: dwxgmac2: add XGMAC timestamp interrupt support
From: Zxyan Zhu <hidden>
Date: 2026-08-10 10:02:53
Also in:
linux-arm-kernel, lkml
Subsystem:
networking drivers, stmmac ethernet driver, the rest · Maintainers:
Andrew Lunn, "David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Maxime Chevallier, Linus Torvalds
DWXGMAC2 uses XGMAC_TIMESTAMP_STATUS at offset 0xd20, while the generic stmmac PTP handler reads the dwmac4 offset GMAC_TIMESTAMP_STATUS (0xb20). Before this change, the DWXGMAC2 and DWXLGMAC2 hwif entries used &stmmac_ptp, whose timestamp_interrupt callback read the wrong register and whose config_hw_tstamping callback never enabled the XGMAC timestamp interrupt (XGMAC_TSIE was not in XGMAC_INT_DEFAULT_EN). As a result, auxiliary snapshot events were never reported on XGMAC platforms. Add a dedicated DWXGMAC2 timestamp interrupt handler that: - reads XGMAC_TIMESTAMP_STATUS before checking STMMAC_FLAG_EXT_SNAPSHOT_EN, so that the timestamp interrupt status is cleared even when auxiliary snapshots are disabled - derives the pending auxiliary snapshot count from the persistent ATSNS field instead of the transient AUXTSTRIG status bit - generates the corresponding PTP_CLOCK_EXTTS events Also enable XGMAC_TSIE in XGMAC_INT_DEFAULT_EN and hook the new handler into the DWXGMAC2 and DWXLGMAC2 hwif entries. Signed-off-by: Zxyan Zhu <redacted> --- v1: https://lore.kernel.org/netdev/20260806-dwxgmac2-timestamp-irq-v1-1-c051c79c9d90@gmail.com/ (local) v2: - reads XGMAC_TIMESTAMP_STATUS before checking STMMAC_FLAG_EXT_SNAPSHOT_EN, so that the timestamp interrupt status is cleared even when auxiliary snapshots are disabled. - Drop the unnecessary (u64) cast in dwxgmac2_get_mac_tx_timestamp(). - Reword the changelog to describe the real problem: the generic handler read the wrong register offset (0xb20 vs 0xd20) and the interrupt was never enabled, so auxiliary snapshot reporting never worked on XGMAC. - Update the comment to clarify that TXTSC is cleared by XGMAC_TXTIMESTAMP_SEC, not by XGMAC_TIMESTAMP_STATUS. --- .../net/ethernet/stmicro/stmmac/dwxgmac2.h | 2 +- .../ethernet/stmicro/stmmac/dwxgmac2_core.c | 43 +++++++++++++++++++ drivers/net/ethernet/stmicro/stmmac/hwif.c | 4 +- drivers/net/ethernet/stmicro/stmmac/hwif.h | 1 + .../ethernet/stmicro/stmmac/stmmac_hwtstamp.c | 12 ++++++ .../net/ethernet/stmicro/stmmac/stmmac_ptp.h | 1 + 6 files changed, 60 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
index 61b6d45a02f5..76e2860a9517 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2.h@@ -87,7 +87,7 @@ #define XGMAC_TSIE BIT(12) #define XGMAC_LPIIE BIT(5) #define XGMAC_PMTIE BIT(4) -#define XGMAC_INT_DEFAULT_EN (XGMAC_LPIIE | XGMAC_PMTIE) +#define XGMAC_INT_DEFAULT_EN (XGMAC_LPIIE | XGMAC_PMTIE | XGMAC_TSIE) #define XGMAC_Qx_TX_FLOW_CTRL(x) (0x00000070 + (x) * 4) #define XGMAC_PT GENMASK(31, 16) #define XGMAC_TFE BIT(1)
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
index f02b434bbd50..b849cebf9b29 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwxgmac2_core.c@@ -1154,6 +1154,49 @@ static int dwxgmac2_get_mac_tx_timestamp(struct mac_device_info *hw, u64 *ts) return 0; } +void dwxgmac2_timestamp_interrupt(struct stmmac_priv *priv) +{ + u32 ts_status, pending_snapshots, acr_value, channel; + struct ptp_clock_event event; + unsigned long flags; + u64 ptp_time; + int i; + + /* Read XGMAC_TIMESTAMP_STATUS to get the AUX snapshot + * count. This read also clears the TSIS bit in + * XGMAC_INT_STATUS. + * TX timestamp polling may have already cleared TSIS + * and AUXTSTRIG, so rely on ATSNS instead. + * TXTSC is cleared by XGMAC_TXTIMESTAMP_SEC, not by + * this register, so there is no conflict. + */ + ts_status = readl(priv->ioaddr + XGMAC_TIMESTAMP_STATUS); + + if (!(priv->plat->flags & STMMAC_FLAG_EXT_SNAPSHOT_EN)) + return; + + pending_snapshots = FIELD_GET(XGMAC_TIMESTAMP_ATSNS_MASK, ts_status); + if (!pending_snapshots) + return; + + acr_value = readl(priv->ptpaddr + PTP_ACR); + channel = FIELD_GET(PTP_ACR_MASK, acr_value); + if (!channel) + return; + channel = ilog2(channel); + + for (i = 0; i < pending_snapshots; i++) { + read_lock_irqsave(&priv->ptp_lock, flags); + stmmac_get_ptptime(priv, priv->ptpaddr, &ptp_time); + read_unlock_irqrestore(&priv->ptp_lock, flags); + + event.type = PTP_CLOCK_EXTTS; + event.index = channel; + event.timestamp = ptp_time; + ptp_clock_event(priv->ptp_clock, &event); + } +} + static int dwxgmac2_flex_pps_config(void __iomem *ioaddr, int index, struct stmmac_pps_cfg *cfg, bool enable, u32 sub_second_inc, u32 systime_flags)
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.c b/drivers/net/ethernet/stmicro/stmmac/hwif.c
index 511b0fd5e834..9718582b8480 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.c
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.c@@ -258,7 +258,7 @@ static const struct stmmac_hwif_entry { .dma = &dwxgmac210_dma_ops, .mac = &dwxgmac210_ops, .vlan = &dwxgmac210_vlan_ops, - .hwtimestamp = &stmmac_ptp, + .hwtimestamp = &dwxgmac2_ptp, .ptp = &stmmac_ptp_clock_ops, .mode = NULL, .tc = &dwmac510_tc_ops,
@@ -280,7 +280,7 @@ static const struct stmmac_hwif_entry { .dma = &dwxgmac210_dma_ops, .mac = &dwxlgmac2_ops, .vlan = &dwxlgmac2_vlan_ops, - .hwtimestamp = &stmmac_ptp, + .hwtimestamp = &dwxgmac2_ptp, .ptp = &stmmac_ptp_clock_ops, .mode = NULL, .tc = &dwmac510_tc_ops,
diff --git a/drivers/net/ethernet/stmicro/stmmac/hwif.h b/drivers/net/ethernet/stmicro/stmmac/hwif.h
index e6317b94fff7..818ab3daa91c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/hwif.h
+++ b/drivers/net/ethernet/stmicro/stmmac/hwif.h@@ -671,6 +671,7 @@ extern const struct stmmac_desc_ops ndesc_ops; extern const struct stmmac_hwtimestamp stmmac_ptp; extern const struct stmmac_hwtimestamp dwmac1000_ptp; +extern const struct stmmac_hwtimestamp dwxgmac2_ptp; extern const struct stmmac_mode_ops ring_mode_ops; extern const struct stmmac_mode_ops chain_mode_ops;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
index b9a985fa772c..9d7d24259abd 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c@@ -277,3 +277,15 @@ const struct stmmac_hwtimestamp dwmac1000_ptp = { .get_ptptime = dwmac1000_get_ptptime, .timestamp_interrupt = dwmac1000_timestamp_interrupt, }; + +const struct stmmac_hwtimestamp dwxgmac2_ptp = { + .config_hw_tstamping = config_hw_tstamping, + .init_systime = init_systime, + .config_sub_second_increment = config_sub_second_increment, + .config_addend = config_addend, + .adjust_systime = adjust_systime, + .get_systime = get_systime, + .get_ptptime = get_ptptime, + .timestamp_interrupt = dwxgmac2_timestamp_interrupt, + .hwtstamp_correct_latency = hwtstamp_correct_latency, +};
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h
index 3fe0e3a80e80..dade09614163 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.h@@ -103,6 +103,7 @@ int dwmac1000_ptp_enable(struct ptp_clock_info *ptp, void dwmac1000_get_ptptime(void __iomem *ptpaddr, u64 *ptp_time); void dwmac1000_timestamp_interrupt(struct stmmac_priv *priv); +void dwxgmac2_timestamp_interrupt(struct stmmac_priv *priv); extern const struct ptp_clock_info stmmac_ptp_clock_ops; extern const struct ptp_clock_info dwmac1000_ptp_clock_ops;
--
2.34.1