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[B,1/1] qede: Handle infinite driver spinning for Tx timestamp.

Message ID 20191218185752.8529-2-gpiccoli@canonical.com
State New
Headers show
Series Fix for qede driver causing 100% CPU load | expand

Commit Message

Guilherme G. Piccoli Dec. 18, 2019, 6:57 p.m. UTC 
From: Sudarsana Reddy Kalluru <skalluru@marvell.com>

BugLink: https://bugs.launchpad.net/bugs/1855409

In PTP Tx implementation, driver kept scheduling a poll thread until the
timestamp is available. In the error scenarios (e.g. app requesting the
timestamp for non-ptp packet), this thread kept waiting for the timestamp
forever.  This patch add changes to report such scenario as an error and
terminate the thread. Added a timeout of 2 seconds i.e., max time to wait
for Tx timestamp. Added a stat value ptp_skip_txts for reporting the number
of packets for which Tx timestamping is skipped.

Signed-off-by: Sudarsana Reddy Kalluru <skalluru@marvell.com>
Signed-off-by: Michal Kalderon <mkalderon@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(backported from commit 9adebac37e7d26c5cd73776a0279574afe3f410b)
[gpiccoli: context adjustments due to the following missing commits:
- 32d26a685c18: Added a link change statistics;
- 149d3775f108: Changed ancestor to access qede-flags;
- ccc67ef50b90: Added error recovery process.
Due to these, small conflicts arose demanding adjustments.]
Signed-off-by: Guilherme G. Piccoli <gpiccoli@canonical.com>
---
 drivers/net/ethernet/qlogic/qede/qede.h       |  2 +
 .../net/ethernet/qlogic/qede/qede_ethtool.c   |  2 +
 drivers/net/ethernet/qlogic/qede/qede_main.c  |  4 ++
 drivers/net/ethernet/qlogic/qede/qede_ptp.c   | 37 +++++++++++++++----
 4 files changed, 38 insertions(+), 7 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/ethernet/qlogic/qede/qede.h b/drivers/net/ethernet/qlogic/qede/qede.h
index a3a70ade411f..abc74df1042a 100644
--- a/drivers/net/ethernet/qlogic/qede/qede.h
+++ b/drivers/net/ethernet/qlogic/qede/qede.h
@@ -86,6 +86,7 @@  struct qede_stats_common {
 	u64 coalesced_aborts_num;
 	u64 non_coalesced_pkts;
 	u64 coalesced_bytes;
+	u64 ptp_skip_txts;
 
 	/* port */
 	u64 rx_64_byte_packets;
@@ -178,6 +179,7 @@  struct qede_dev {
 
 	const struct qed_eth_ops	*ops;
 	struct qede_ptp			*ptp;
+	u64				ptp_skip_txts;
 
 	struct qed_dev_eth_info dev_info;
 #define QEDE_MAX_RSS_CNT(edev)	((edev)->dev_info.num_queues)
diff --git a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
index dae741270022..39f1d18c96eb 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_ethtool.c
@@ -170,6 +170,8 @@  static const struct {
 	QEDE_STAT(coalesced_aborts_num),
 	QEDE_STAT(non_coalesced_pkts),
 	QEDE_STAT(coalesced_bytes),
+
+	QEDE_STAT(ptp_skip_txts),
 };
 
 #define QEDE_NUM_STATS	ARRAY_SIZE(qede_stats_arr)
diff --git a/drivers/net/ethernet/qlogic/qede/qede_main.c b/drivers/net/ethernet/qlogic/qede/qede_main.c
index 552cf45ddcbb..b5b3e2f877d0 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_main.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_main.c
@@ -393,6 +393,7 @@  void qede_fill_by_demand_stats(struct qede_dev *edev)
 	p_common->brb_truncates = stats.common.brb_truncates;
 	p_common->brb_discards = stats.common.brb_discards;
 	p_common->tx_mac_ctrl_frames = stats.common.tx_mac_ctrl_frames;
+	p_common->ptp_skip_txts = edev->ptp_skip_txts;
 
 	if (QEDE_IS_BB(edev)) {
 		struct qede_stats_bb *p_bb = &edev->stats.bb;
@@ -2008,6 +2009,9 @@  static void qede_unload(struct qede_dev *edev, enum qede_unload_mode mode,
 out:
 	if (!is_locked)
 		__qede_unlock(edev);
+
+	edev->ptp_skip_txts = 0;
+
 	DP_INFO(edev, "Ending qede unload\n");
 }
 
diff --git a/drivers/net/ethernet/qlogic/qede/qede_ptp.c b/drivers/net/ethernet/qlogic/qede/qede_ptp.c
index 812e831ed250..fb74dd9f38f0 100644
--- a/drivers/net/ethernet/qlogic/qede/qede_ptp.c
+++ b/drivers/net/ethernet/qlogic/qede/qede_ptp.c
@@ -30,6 +30,7 @@ 
  * SOFTWARE.
  */
 #include "qede_ptp.h"
+#define QEDE_PTP_TX_TIMEOUT (2 * HZ)
 
 struct qede_ptp {
 	const struct qed_eth_ptp_ops	*ops;
@@ -38,6 +39,7 @@  struct qede_ptp {
 	struct timecounter		tc;
 	struct ptp_clock		*clock;
 	struct work_struct		work;
+	unsigned long			ptp_tx_start;
 	struct qede_dev			*edev;
 	struct sk_buff			*tx_skb;
 
@@ -160,18 +162,30 @@  static void qede_ptp_task(struct work_struct *work)
 	struct qede_dev *edev;
 	struct qede_ptp *ptp;
 	u64 timestamp, ns;
+	bool timedout;
 	int rc;
 
 	ptp = container_of(work, struct qede_ptp, work);
 	edev = ptp->edev;
+	timedout = time_is_before_jiffies(ptp->ptp_tx_start +
+					  QEDE_PTP_TX_TIMEOUT);
 
 	/* Read Tx timestamp registers */
 	spin_lock_bh(&ptp->lock);
 	rc = ptp->ops->read_tx_ts(edev->cdev, &timestamp);
 	spin_unlock_bh(&ptp->lock);
 	if (rc) {
-		/* Reschedule to keep checking for a valid timestamp value */
-		schedule_work(&ptp->work);
+		if (unlikely(timedout)) {
+			DP_INFO(edev, "Tx timestamp is not recorded\n");
+			dev_kfree_skb_any(ptp->tx_skb);
+			ptp->tx_skb = NULL;
+			clear_bit_unlock(QEDE_FLAGS_PTP_TX_IN_PRORGESS,
+					 &edev->flags);
+			edev->ptp_skip_txts++;
+		} else {
+			/* Reschedule to keep checking for a valid TS value */
+			schedule_work(&ptp->work);
+		}
 		return;
 	}
 
@@ -514,19 +528,28 @@  void qede_ptp_tx_ts(struct qede_dev *edev, struct sk_buff *skb)
 	if (!ptp)
 		return;
 
-	if (test_and_set_bit_lock(QEDE_FLAGS_PTP_TX_IN_PRORGESS, &edev->flags))
+	if (test_and_set_bit_lock(QEDE_FLAGS_PTP_TX_IN_PRORGESS,
+				  &edev->flags)) {
+		DP_ERR(edev, "Timestamping in progress\n");
+		edev->ptp_skip_txts++;
 		return;
+	}
 
 	if (unlikely(!(edev->flags & QEDE_TX_TIMESTAMPING_EN))) {
-		DP_NOTICE(edev,
-			  "Tx timestamping was not enabled, this packet will not be timestamped\n");
+		DP_ERR(edev,
+		       "Tx timestamping was not enabled, this packet will not be timestamped\n");
+		clear_bit_unlock(QEDE_FLAGS_PTP_TX_IN_PRORGESS, &edev->flags);
+		edev->ptp_skip_txts++;
 	} else if (unlikely(ptp->tx_skb)) {
-		DP_NOTICE(edev,
-			  "The device supports only a single outstanding packet to timestamp, this packet will not be timestamped\n");
+		DP_ERR(edev,
+		       "The device supports only a single outstanding packet to timestamp, this packet will not be timestamped\n");
+		clear_bit_unlock(QEDE_FLAGS_PTP_TX_IN_PRORGESS, &edev->flags);
+		edev->ptp_skip_txts++;
 	} else {
 		skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
 		/* schedule check for Tx timestamp */
 		ptp->tx_skb = skb_get(skb);
+		ptp->ptp_tx_start = jiffies;
 		schedule_work(&ptp->work);
 	}
 }