From 96c88268b79bc0af2014b8732a438a7afc4fff0d Mon Sep 17 00:00:00 2001 From: Gatien Chevallier Date: Mon, 1 Sep 2025 11:16:27 +0200 Subject: [PATCH 1/2] time: export timespec64_add_safe() symbol Export the timespec64_add_safe() symbol so that this function can be used in modules where computation of time related is done. Signed-off-by: Gatien Chevallier Acked-by: Thomas Gleixner Link: https://patch.msgid.link/20250901-relative_flex_pps-v4-1-b874971dfe85@foss.st.com Signed-off-by: Jakub Kicinski --- kernel/time/time.c | 1 + 1 file changed, 1 insertion(+) diff --git a/kernel/time/time.c b/kernel/time/time.c index 1b69caa87480..0ba8e3c50d62 100644 --- a/kernel/time/time.c +++ b/kernel/time/time.c @@ -858,6 +858,7 @@ struct timespec64 timespec64_add_safe(const struct timespec64 lhs, return res; } +EXPORT_SYMBOL_GPL(timespec64_add_safe); /** * get_timespec64 - get user's time value into kernel space From adbe2cfd8a93fdefb2bd238c1ccd22d2c40e8499 Mon Sep 17 00:00:00 2001 From: Gatien Chevallier Date: Mon, 1 Sep 2025 11:16:28 +0200 Subject: [PATCH 2/2] drivers: net: stmmac: handle start time set in the past for flexible PPS In case the time arguments used for flexible PPS signal generation are in the past, consider the arguments to be a time offset relative to the MAC system time. This way, past time use case is handled and it avoids the tedious work of passing an absolute time value for the flexible PPS signal generation while not breaking existing scripts that may rely on this behavior. Signed-off-by: Gatien Chevallier Link: https://patch.msgid.link/20250901-relative_flex_pps-v4-2-b874971dfe85@foss.st.com Signed-off-by: Jakub Kicinski --- .../net/ethernet/stmicro/stmmac/stmmac_ptp.c | 34 ++++++++++++++++++- 1 file changed, 33 insertions(+), 1 deletion(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c index 3767ba495e78..ecbff20771f4 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c @@ -10,6 +10,8 @@ #include "stmmac.h" #include "stmmac_ptp.h" +#define PTP_SAFE_TIME_OFFSET_NS 500000 + /** * stmmac_adjust_freq * @@ -171,7 +173,11 @@ static int stmmac_enable(struct ptp_clock_info *ptp, u32 acr_value; switch (rq->type) { - case PTP_CLK_REQ_PEROUT: + case PTP_CLK_REQ_PEROUT: { + struct timespec64 curr_time; + u64 target_ns = 0; + u64 ns = 0; + /* Reject requests with unsupported flags */ if (rq->perout.flags) return -EOPNOTSUPP; @@ -180,6 +186,31 @@ static int stmmac_enable(struct ptp_clock_info *ptp, cfg->start.tv_sec = rq->perout.start.sec; cfg->start.tv_nsec = rq->perout.start.nsec; + + /* A time set in the past won't trigger the start of the flexible PPS generation for + * the GMAC5. For some reason it does for the GMAC4 but setting a time in the past + * should be addressed anyway. Therefore, any value set it the past is considered as + * an offset compared to the current MAC system time. + * Be aware that an offset too low may not trigger flexible PPS generation + * if time spent in this configuration makes the targeted time already outdated. + * To address this, add a safe time offset. + */ + if (!cfg->start.tv_sec && cfg->start.tv_nsec < PTP_SAFE_TIME_OFFSET_NS) + cfg->start.tv_nsec += PTP_SAFE_TIME_OFFSET_NS; + + target_ns = cfg->start.tv_nsec + ((u64)cfg->start.tv_sec * NSEC_PER_SEC); + + stmmac_get_systime(priv, priv->ptpaddr, &ns); + if (ns > TIME64_MAX - PTP_SAFE_TIME_OFFSET_NS) + return -EINVAL; + + curr_time = ns_to_timespec64(ns); + if (target_ns < ns + PTP_SAFE_TIME_OFFSET_NS) { + cfg->start = timespec64_add_safe(cfg->start, curr_time); + if (cfg->start.tv_sec == TIME64_MAX) + return -EINVAL; + } + cfg->period.tv_sec = rq->perout.period.sec; cfg->period.tv_nsec = rq->perout.period.nsec; @@ -190,6 +221,7 @@ static int stmmac_enable(struct ptp_clock_info *ptp, priv->systime_flags); write_unlock_irqrestore(&priv->ptp_lock, flags); break; + } case PTP_CLK_REQ_EXTTS: { u8 channel;