[PATCH net v3] net: stmmac: propagate PTP addend and system time programming errors

@@ -601,31 +601,64 @@ static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv, struct dma_desc *p,
 	}
 }
 
-static void stmmac_update_subsecond_increment(struct stmmac_priv *priv)
+static void stmmac_restore_subsecond_increment(struct stmmac_priv *priv,
+					       u32 default_addend)
 {
 	bool xmac = dwmac_is_xmac(priv->plat->core_type);
 	u32 sec_inc = 0;
-	u64 temp = 0;
 
+	stmmac_config_addend(priv, priv->ptpaddr, default_addend);
 	stmmac_config_hw_tstamping(priv, priv->ptpaddr, priv->systime_flags);
+	stmmac_config_sub_second_increment(priv, priv->ptpaddr,
+					   priv->plat->clk_ptp_rate,
+					   xmac, &sec_inc);
+	priv->default_addend = default_addend;
+	priv->sub_second_inc = sec_inc;
+}
+
+static int stmmac_update_subsecond_increment(struct stmmac_priv *priv,
+					     u32 systime_flags)
+{
+	bool xmac = dwmac_is_xmac(priv->plat->core_type);
+	u32 sec_inc = 0, val;
+	u64 temp = 0;
+	int ret;
+
+	stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags);
 
 	/* program Sub Second Increment reg */
 	stmmac_config_sub_second_increment(priv, priv->ptpaddr,
 					   priv->plat->clk_ptp_rate,
 					   xmac, &sec_inc);
-	temp = div_u64(1000000000ULL, sec_inc);
-
-	/* Store sub second increment for later use */
-	priv->sub_second_inc = sec_inc;
+	if (!sec_inc) {
+		ret = -EINVAL;
+		goto error;
+	}
 
 	/* calculate default added value:
 	 * formula is :
 	 * addend = (2^32)/freq_div_ratio;
 	 * where, freq_div_ratio = 1e9ns/sec_inc
 	 */
+	temp = div_u64(1000000000ULL, sec_inc);
 	temp = (u64)(temp << 32);
-	priv->default_addend = div_u64(temp, priv->plat->clk_ptp_rate);
-	stmmac_config_addend(priv, priv->ptpaddr, priv->default_addend);
+	val = div_u64(temp, priv->plat->clk_ptp_rate);
+
+	ret = stmmac_config_addend(priv, priv->ptpaddr, val);
+	if (ret)
+		goto error;
+
+	priv->sub_second_inc = sec_inc;
+	priv->default_addend = val;
+
+	return 0;
+error:
+	/* Restore previous configuration */
+	stmmac_config_hw_tstamping(priv, priv->ptpaddr, priv->systime_flags);
+	stmmac_config_sub_second_increment(priv, priv->ptpaddr,
+					   priv->plat->clk_ptp_rate, xmac,
+					   NULL);
+	return ret;
 }
 
 /**

@@ -854,35 +887,42 @@ static int stmmac_hwtstamp_get(struct net_device *dev,
 /**
  * stmmac_init_tstamp_counter - init hardware timestamping counter
  * @priv: driver private structure
- * @systime_flags: timestamping flags
  * Description:
  * Initialize hardware counter for packet timestamping.
  * This is valid as long as the interface is open and not suspended.
  * Will be rerun after resuming from suspend, case in which the timestamping
  * flags updated by stmmac_hwtstamp_set() also need to be restored.
  */
-static int stmmac_init_tstamp_counter(struct stmmac_priv *priv,
-				      u32 systime_flags)
+static int stmmac_init_tstamp_counter(struct stmmac_priv *priv)
 {
+	u32 default_addend = priv->default_addend;
 	struct timespec64 now;
+	int ret;
 
 	if (!priv->plat->clk_ptp_rate) {
 		netdev_err(priv->dev, "Invalid PTP clock rate");
 		return -EINVAL;
 	}
 
-	stmmac_config_hw_tstamping(priv, priv->ptpaddr, systime_flags);
-	priv->systime_flags = systime_flags;
-
-	stmmac_update_subsecond_increment(priv);
+	ret = stmmac_update_subsecond_increment(priv, priv->systime_flags);
+	if (ret)
+		return ret;
 
 	/* initialize system time */
 	ktime_get_real_ts64(&now);
 
 	/* lower 32 bits of tv_sec are safe until y2106 */
-	stmmac_init_systime(priv, priv->ptpaddr, (u32)now.tv_sec, now.tv_nsec);
+	ret = stmmac_init_systime(priv, priv->ptpaddr, (u32)now.tv_sec,
+				  now.tv_nsec);
+	if (ret)
+		goto error;
 
 	return 0;
+error:
+	/* Restore previous configuration */
+	stmmac_restore_subsecond_increment(priv, default_addend);
+
+	return ret;
 }
 
 /**

@@ -905,8 +945,14 @@ static int stmmac_init_timestamping(struct stmmac_priv *priv)
 		return -EOPNOTSUPP;
 	}
 
-	ret = stmmac_init_tstamp_counter(priv, STMMAC_HWTS_ACTIVE |
-					       PTP_TCR_TSCFUPDT);
+	/* Reset hw ts configuration */
+	memset(&priv->tstamp_config, 0, sizeof(priv->tstamp_config));
+	priv->systime_flags = STMMAC_HWTS_ACTIVE | PTP_TCR_TSCFUPDT;
+	priv->tsfupdt_coarse = false;
+	priv->hwts_tx_en = 0;
+	priv->hwts_rx_en = 0;
+
+	ret = stmmac_init_tstamp_counter(priv);
 	if (ret) {
 		netdev_warn(priv->dev, "PTP init failed\n");
 		return ret;

@@ -927,10 +973,6 @@ static int stmmac_init_timestamping(struct stmmac_priv *priv)
 		netdev_info(priv->dev,
 			    "IEEE 1588-2008 Advanced Timestamp supported\n");
 
-	memset(&priv->tstamp_config, 0, sizeof(priv->tstamp_config));
-	priv->hwts_tx_en = 0;
-	priv->hwts_rx_en = 0;
-
 	if (priv->plat->flags & STMMAC_FLAG_HWTSTAMP_CORRECT_LATENCY)
 		stmmac_hwtstamp_correct_latency(priv, priv);
 

@@ -7711,18 +7753,26 @@ static int stmmac_dl_ts_coarse_set(struct devlink *dl, u32 id,
 {
 	struct stmmac_devlink_priv *dl_priv = devlink_priv(dl);
 	struct stmmac_priv *priv = dl_priv->stmmac_priv;
+	u32 systime_flags = priv->systime_flags;
+	int ret;
 
-	priv->tsfupdt_coarse = ctx->val.vbool;
-
-	if (priv->tsfupdt_coarse)
-		priv->systime_flags &= ~PTP_TCR_TSCFUPDT;
+	if (ctx->val.vbool)
+		systime_flags &= ~PTP_TCR_TSCFUPDT;
 	else
-		priv->systime_flags |= PTP_TCR_TSCFUPDT;
+		systime_flags |= PTP_TCR_TSCFUPDT;
 
 	/* In Coarse mode, we can use a smaller subsecond increment, let's
 	 * reconfigure the systime, subsecond increment and addend.
 	 */
-	stmmac_update_subsecond_increment(priv);
+	ret = stmmac_update_subsecond_increment(priv, systime_flags);
+	if (ret) {
+		NL_SET_ERR_MSG_MOD(extack,
+				   "failed to reconfigure PTP adjustment");
+		return ret;
+	}
+
+	priv->tsfupdt_coarse = ctx->val.vbool;
+	priv->systime_flags = systime_flags;
 
 	return 0;
 }

@@ -28,14 +28,15 @@ static int stmmac_adjust_freq(struct ptp_clock_info *ptp, long scaled_ppm)
 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
 	unsigned long flags;
 	u32 addend;
+	int ret;
 
 	addend = adjust_by_scaled_ppm(priv->default_addend, scaled_ppm);
 
 	write_lock_irqsave(&priv->ptp_lock, flags);
-	stmmac_config_addend(priv, priv->ptpaddr, addend);
+	ret = stmmac_config_addend(priv, priv->ptpaddr, addend);
 	write_unlock_irqrestore(&priv->ptp_lock, flags);
 
-	return 0;
+	return ret;
 }
 
 /**

@@ -153,12 +154,13 @@ static int stmmac_set_time(struct ptp_clock_info *ptp,
 	struct stmmac_priv *priv =
 	    container_of(ptp, struct stmmac_priv, ptp_clock_ops);
 	unsigned long flags;
+	int ret;
 
 	write_lock_irqsave(&priv->ptp_lock, flags);
-	stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
+	ret = stmmac_init_systime(priv, priv->ptpaddr, ts->tv_sec, ts->tv_nsec);
 	write_unlock_irqrestore(&priv->ptp_lock, flags);
 
-	return 0;
+	return ret;
 }
 
 static int stmmac_enable(struct ptp_clock_info *ptp,