bnxt_en: Retry PTP TX timestamp from FW for 1 second

Use a new default 1 second timeout value instead of the existing
1 msec value.  The driver will keep track of the remaining time
before timeout and will pass this value to bnxt_hwrm_port_ts_query().
The firmware supports timeout values up to 65535 usecs.  If the
timeout value passed to bnxt_hwrm_port_ts_query() is less than the
FW max value, we will use that value to precisely control the
specified timeout.  If it is larger than the FW max value, we will
use the FW max value and any additional retry to reach the desired
timeout will be done in the context of bnxt_ptp_ts_aux_eork().

Link: https://lore.kernel.org/netdev/20240229070202.107488-2-michael.chan@broadcom.com/
Cc: Richard Cochran <richardcochran@gmail.com>
Reviewed-by: Andy Gospodarek <andrew.gospodarek@broadcom.com>
Signed-off-by: Pavan Chebbi <pavan.chebbi@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Reviewed-by: Vadim Fedorenko <vadim.fedorenko@linux.dev>
Link: https://lore.kernel.org/r/20240325222902.220712-3-michael.chan@broadcom.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.c

@@ -678,11 +678,17 @@ static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb)
 {
 	struct bnxt_ptp_cfg *ptp = bp->ptp_cfg;
 	struct skb_shared_hwtstamps timestamp;
+	unsigned long now = jiffies;
 	u64 ts = 0, ns = 0;
+	u32 tmo = 0;
 	int rc;
 
+	if (!ptp->txts_pending)
+		ptp->abs_txts_tmo = now + msecs_to_jiffies(ptp->txts_tmo);
+	if (!time_after_eq(now, ptp->abs_txts_tmo))
+		tmo = jiffies_to_msecs(ptp->abs_txts_tmo - now);
 	rc = bnxt_hwrm_port_ts_query(bp, PORT_TS_QUERY_REQ_FLAGS_PATH_TX, &ts,
-				     0);
+				     tmo);
 	if (!rc) {
 		memset(&timestamp, 0, sizeof(timestamp));
 		spin_lock_bh(&ptp->ptp_lock);
@@ -691,6 +697,10 @@ static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb)
 		timestamp.hwtstamp = ns_to_ktime(ns);
 		skb_tstamp_tx(ptp->tx_skb, &timestamp);
 	} else {
+		if (!time_after_eq(jiffies, ptp->abs_txts_tmo)) {
+			ptp->txts_pending = true;
+			return;
+		}
 		netdev_warn_once(bp->dev,
 				 "TS query for TX timer failed rc = %x\n", rc);
 	}
@@ -698,6 +708,7 @@ static void bnxt_stamp_tx_skb(struct bnxt *bp, struct sk_buff *skb)
 	dev_kfree_skb_any(ptp->tx_skb);
 	ptp->tx_skb = NULL;
 	atomic_inc(&ptp->tx_avail);
+	ptp->txts_pending = false;
 }
 
 static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
@@ -721,6 +732,8 @@ static long bnxt_ptp_ts_aux_work(struct ptp_clock_info *ptp_info)
 		spin_unlock_bh(&ptp->ptp_lock);
 		ptp->next_overflow_check = now + BNXT_PHC_OVERFLOW_PERIOD;
 	}
+	if (ptp->txts_pending)
+		return 0;
 	return HZ;
 }
 
@@ -973,6 +986,7 @@ int bnxt_ptp_init(struct bnxt *bp, bool phc_cfg)
 		spin_unlock_bh(&ptp->ptp_lock);
 		ptp_schedule_worker(ptp->ptp_clock, 0);
 	}
+	ptp->txts_tmo = BNXT_PTP_DFLT_TX_TMO;
 	return 0;
 
 out:

drivers/net/ethernet/broadcom/bnxt/bnxt_ptp.h

@@ -22,6 +22,7 @@
 #define BNXT_LO_TIMER_MASK	0x0000ffffffffUL
 #define BNXT_HI_TIMER_MASK	0xffff00000000UL
 
+#define BNXT_PTP_DFLT_TX_TMO	1000 /* ms */
 #define BNXT_PTP_QTS_TIMEOUT	1000
 #define BNXT_PTP_QTS_MAX_TMO_US	65535
 #define BNXT_PTP_QTS_TX_ENABLES	(PORT_TS_QUERY_REQ_ENABLES_PTP_SEQ_ID |	\
@@ -116,11 +117,14 @@ struct bnxt_ptp_cfg {
 					 BNXT_PTP_MSG_PDELAY_REQ |	\
 					 BNXT_PTP_MSG_PDELAY_RESP)
 	u8			tx_tstamp_en:1;
+	u8			txts_pending:1;
 	int			rx_filter;
 	u32			tstamp_filters;
 
 	u32			refclk_regs[2];
 	u32			refclk_mapped_regs[2];
+	u32			txts_tmo;
+	unsigned long		abs_txts_tmo;
 };
 
 #if BITS_PER_LONG == 32